Well, we all know what a first kiss is, so let's just get down to the trope.
An individual's first kiss will generally be the subject of a great deal of nervousness. It may be preceded by some Kissing Warm Up. Subjects (usually teenaged) will approach one another tentatively. They'll want it to be perfect, and with the perfect person, and when it inevitably isn't... well, it'll turn out all right anyway. In Japan, where the culture is more strict, the first kiss is an even bigger deal; Sacred First Kiss has more details.
A couple's first kiss will be the subject of much squeeing among fans, who have had to suffer through Will They or Won't They? for months or years. It may end the UST and result in a Relationship Upgrade, or may be sacrificed at the altar of the god, Status Quo. These kisses tend to be made in times of high stress, because the participants Cannot Spit It Out under normal circumstances. This often becomes a Big Damn Kiss, especially in action-packed dramas.
Anime and Manga
- Pokémon: Ash's first kiss is presumably with Bianca from the fifth movie, Pokémon Heroes (or the Olympus Mons that looks like her). Brock and Misty are noticeably shocked - Misty even drops Togepi!
- Parodied to some extent in Love Hina with Kaolla Su's chart. Keitaro's first -> Mutsumi. Naru's -> Also Mutsumi (she was saying hi both times) Motoko -> a kissing robot. Shinobu -> Tama the turtle. Koalla Su -> Motoko's face is there, but it says it's her second.
- It's Motoko's second, obviously, and Su's first.
- In Negima, one of the complications of the Pactio kiss is that for most of the girls involved, it's also their first.
- Tengen Toppa Gurren Lagann's first real heartwarming moment was Kamina asking Yoko to watch his back during battle. She called out his name and when he turned around, she leaned in and kissed him, saying "your rear really is defenseless, isn't it?" His surprise lasted a moment until he decided to take it further and kissed her back. Too bad the latter was also their Last Kiss as Kamina died at the end of the episode.
- Neon Genesis Evangelion subverted this, as usual. In episode 15, Asuka asked Shinji if he wants to kiss since she's bored. He initially resisted until she pulled a low blow by asking if he's afraid of kissing a girl on the anniversary of his mother's death. They went forward with the kiss though Asuka held Shinji's nose the whole time since his breath was tickling her (at least that was her excuse). When he broke it off due to borderline asphyxiation, she ran into the bathroom and rinsed her mouth, exclaiming that she should never kiss anyone to kill time ever again.
- This was brought up again during the infamous Mind Rape scene. When Shinji came up in her head, she exclaimed "What are you doing there?! You won't do anything! You won't help me! You won't even hold me!" And it's shown that after their first kiss, she ran to the bathroom to gargle so she could hide her pain from him about his lack of warmth.
- MAR has Ginta sharing his first kiss with Snow, and it's also her first kiss. Snow is also the in-universe Expy of the girl he wishes he could share his first kiss with. Koyuki also acts as if this is her first kiss, despite it actually being another person.
- Dio steals Jonathan's girlfriend Erina's first kiss in the first part of Jo Jos Bizarre Adventure. And then he brags about it. This starts a Humiliation Conga - his.
- Parodied to hell and back in Kodomo no Omocha. Sana's first kiss is with Akito, who kisses her in public... and she reacts LOUDLY to it.
- Akito's first kiss had been given as a kindergartener for 60 yen. Later, he finds out that the story of the first kiss ruined the kissed girl (Fuuka)'s love story.
- InThe World God Only Knows, most of the girls that Keima had captured most likely had their first kiss taken by Keima when he kissed them to capture the runaway spirits inhabiting their bodies. By that prospect, when Keima took Tenri's first kiss, he also took Diana's first kiss. And later on when he did the same with Tsukiyo, he took Vulcan's first kiss. Not to mention Keima's First Kiss was taken by Ayumi, the first girl he captured in the beginning of the series.
- There's a complicated example in a later chapter. Keima takes Chihiro to a secluded spot, and when the moment is right, pushes her down on a bench and gets on top of her. She mentions "It's my first time," but she means the kiss that's coming. The problem is, it's not her first kiss, which he knows for a fact because he's the one who kissed her. And the entire reason he was pursuing her was because he thought she remembered that, which would mean she was immune to the memory-wipe, which would mean she had a goddess inside her. He figures this all out in seconds, and realizes it means he has the wrong girl.
- Ranma ½: In the anime, Ranma and Shampoo, much to Akane Tendo's ire.
- In the manga, Ranma's first kiss was forced upon him when in girl form, by a guy he hated - Mikado. He ran away sobbing out of anger and humiliation, especially because it was in front of Akane (and others, but being seen like this by Akane affected him).
- If one counts the time Akane kissed "P-Chan" on his snout, then her first kiss was unintentionally with Ryoga. (No wonder Ranma was furious.) She considers her first kiss to have been with Ranma while he was under the Cat-Fist effects, however.
- In Code Geass, Shirley and Lelouch's First Kiss is tragically subverted; she has just learned her father's been killed, and being emotionally unstable at the time, she kisses Lelouch. She later apologises for it once she's calmed down a bit, saying it wasn't fair on him, and remarks on the irony that despite her long-time crush on him, she can't even be happy that they finally kissed. The fact that, unbeknownst to her, Lelouch is the one who killed her father doesn't make things any better.
- Near the end of the first season, Lelouch gets another First Kiss from C.C, though the psychic powers she uses by physical contact make it unclear what her reasons for doing this are. Still, it's very undeniably one of their main Ship Tease moments.
- In R2, thanks to several rounds of altered memories, Shirley thinks she gets her First Kiss from Lelouch. However, since it's actually Sayoko in disguise, this actually means that their First real Kiss is also their Last Kiss.
- Again in R2, it's very strongly implied that Kallen's first kiss was the one she gave to Lelouch after he declared himself Emperor.
- The Pursuit of Harimao's Treasure: Lupin spends as much time trying to win Diana's affections, as he does searching for the fabled treasure, without success. Still, it wasn't a total loss, since he managed to steal a kiss. Judging by the way she caressed the area of her cheek, where he kissed her, and the way she smiled, afterward, it's implied to have been her first.
- Mamoru steals Usagi's first kiss in Sailor Moon while she's sleeping in the manga, drunk in the first anime. Values Dissonance is a big thing here, as these days kissing someone unconscious is not looked kindly upon; Luna even calls him out on this in Crystal's version of the manga's scene.
- Extremely twisted subversion: In Green Lantern, (enemy) Sinestro Corps member Karu-Sil's origin story looks like it's leading up to this (alien girl's parents are dead, alien girl is taken in by pack of local predators, alien girl meets alien boy)...right up until she caves in his skull with a rock and splits the body with the aforementioned pack of predators. Although one should have seen that coming as she has no lips.
- Another subversion: Rogue from the X-Men had her powers emerge during her first kiss, putting the boy in a permanent coma. Ouch.
- In a Garfield strip, Jon recounts his first kiss, which - true to his nature - ended in a catastrophe, when his braces locked with hers.
- In the Spider-Man comics Peter and MJ share their first kiss (that is their first kiss as a couple-they were both in college at the time and had had on panel relationships with others) in a mostly empty section of JFK airport (well mostly empty sans Robbie Robertson whom was there too) with a big snowy window behind them before Peter went on assignemnt in France. It may not have been upside down, but as MJ said "Wow, why didn't you ever tell me you could kiss!" Followed by after she let it sink in for a minute "Far freaking out." (made even funnier by the fact the kiss was her idea).
- In The Goonies, Andi intends to have her first kiss with Brand but in the darkness, and with her eyes closed, she accidentally kisses his younger brother Mikey instead. She really does believe it was Brand until later, when she gets another chance to kiss him and confirms that only Mikey has braces.
- In Disney's Aladdin, Aladdin's and Jasmine's first kiss indicates their growing love for each other. In general, first kisses in Disney movies are very important and often double as True Love's Kiss.
- Harry Potter, dealing as it does with seven years over the course of some teenager's lives, shows various first kisses in all their awkwardness and complete lack of glamour, no doubt to the rage of many Shippers.
- It is said that Hermione's first kiss ("snog," as Ginny put it) was with Victor Krum (a fellow who seems a perfect gentleman), off-camera.
- After being chewed out for never having been kissed, Ron asserts his *cough* manhood by smooching Lavender Brown after a victorious Quidditch match. Oh, so victorious.
- Harry's first kiss also happens almost off camera. He describes it as "wet".
- The Amber Spyglass gives a slow, tense, and sensuous build-up to Will and Lyra's first, awkward, passionate kiss. It was a pretty powerful one, too. In short, their kiss saved the multiverse.
- Seen in Garth Nix's Sabriel when Touchstone and Sabriel begin to fall under the influence of the bell Astarael, which kills all who hear it, Sabriel exhorts Touchstone to "Think of life!" and kisses him... "savagely." Because she bites his lip as she does this, their kiss is both awkward, passionate, and bloody. It's also damn romantic.
- In John C. Wright's The Orphans of Chaos, the entire matter of first kisses is fraught -- especially with the Laser-Guided Amnesia that is repeatedly inflicted on the main characters, so that some of them have several first kisses.
- In Edgar Rice Burroughs's Chessmen of Mars, this happens right after Tara's profession of love to Turan, and right before her begging him not lead her into dishonor: she's betrothed to another man.
- Percy and Annabeth's first kiss in Percy Jackson and The Olympians: The Battle of the Labyrinth. When Percy was going to battle telekhines and he was in Calypso's island for two weeks after. The fans are still squeeing to this day.
- In Artemis Fowl's sixth book, this happens to Artemis and Holly, after the former had almost died and was rescued by the latter. Cue squeals from supporters.
- In Memoirs of a Geisha, Sayuri mentioned how her kiss with the Chairman was her first real kiss, despite being with other men who kissed her Anywhere but Their Lips.
- In L. Jagi Lamplighter's Prospero Lost, Miranda remembers how Ferdinard snatched a first kiss on the sea journey back home.
- A particularly heartbreaking example comes from The Book Thief. There's a running gag throughout the book in which Rudy keeps trying to get his childhood friend Liesel to kiss him. She finally does, but only after he's been killed in an allied bombing raid.
- In the web-novel Domina Laura steals Derek's first kiss, mostly to keep the other girls from fighting over it.
- In Gene Stratton Porter's Freckles, Angel gives this to Freckles, not even realizing the significance of what she did. Freckles did realize.
- Stacey gets her first kiss from her second summer love Toby in The Baby Sitters Club book #8, Boy-Crazy Stacey.
- In Drake and Josh, Josh waits before explaining a Not What It Looks Like moment to thank God for getting his first kiss, even though he had tried his hardest to repel it.
- In Ned's Declassified School Survival Guide, Ned wanted his first kiss to be with Suzie- along the way he's kissed by the school nurse, the Weasel Mascot and others, reacting with a loud "That didn't count!" each time.
- In the Buffy the Vampire Slayer episode, "All The Way", Dawn shares her first kiss with a boy. From her reaction, he figures out that it was her first. She tries to deny, before admitting that it was her first, and babbling about how bad it must have been for him. He replies by kissing her again. Sadly, he's actually a vampire, and becomes her first staking.
- ICarly: The subject of an episode regarding Freddie's admittance of not having one and Sam mocking him for it on the air. In the aftermath of the fight about Sam broadcasting it to the world, Sam reveals that she hasn't had her first kiss either. The two end up sharing their first kiss together later in the episode. 
- Carly and Freddie's first kiss is in the aftermath of Freddie saving her life by pushing her out of the way of a truck and getting severely hurt.
- Rachel and Ross's first kiss in Friends actually won an Emmy award.
- Despite being much, much older than anyone expected to experience this trope, The Mighty Boosh's Howard Moon gets his first kiss in Party on his birthday, and over-reacts.
- Due to the nature of the show, Home and Away has featured this storyline quite a few times. Among them:
- Maddie spent a large part of an arc trying to get a kiss from Lucas. Fortunately for her, they were both in Colleen's lame duck of a play...which Matilda salvaged admirably.
- Geoff and Melody's relationship (and a large part of Melody's character arc) revolved around this storyline, with Nicole deliberately misinterpreting Melody's description of the kiss in order to make good on a bet.
- In one episode of Frasier, it is revealed that Frasier got beaten up as a result of stealing his first kiss.
- In the episode "Cranes Unplugged", Frasier's son Frederick has his first kiss off-camera.
- The off-screen kiss between Naomi and Emily at that drunken middle school party in Skins was, according to the E4.com character blogs, Naomi's first. (All the boys she dated were too wimpy to go for it; and besides, she'd already seen Emily by then.)
- Glee had a whole episode based on this concept, called (surprisingly enough) Never Been Kissed. In it, we get to see the first kisses of Coach Beiste (with Will Schuester) and Kurt (who had his stolen from him by Karofsky).
- Cory and Topanga's first kiss on Boy Meets World is one of their most iconic moments. The two have just bonded over saving a librarian's job, are chained to a locker, and Topanga plants one on a not-so-willing Cory. The reluctance is due to his immaturity, as he goes on to remember the kiss fondly when he's older and has fallen head over heels in love with Topanga.
- In Doctor Who, the Doctor had his first kiss with his maybe possibly wife, River in the episode "Day of the Moon". It's a somewhat heartbreaking one, however, as it's also River's last kiss with the Doctor.
- There's also the one in the 2010 Christmas Special, between Kazran and Abigail. Kazran is nervous, and asks the Doctor for advice. After telling Kazran to deliberately be Adorkable (since he will be anyway, he might as well make it part of the plan,) he then says:
Doctor: You can either walk over to that beautiful woman or go hide in your room and design a new type of screwdriver.
- Although it might not be for Rinoa (considering her previous relationship with Seifer), it probably is for Squall at the end of Final Fantasy VIII.
- Final Fantasy X. Simply the most exaggerated, beautiful and physics-challenging first kiss ever.
- As lovely as that is (and it is lovely), that is likely not the first kiss for either of them--Tidus' dialogue indicates that he was something of a flirt back in Zanarkand, hence probably has kissed a girl before he came to Spira. And Yuna, well...hers was with Maester Seymour, as seen here, making this, for Yuna, likely an example of the angst that can occur from a "stolen" first kiss. Look out, poor Yuna's first kiss is squicky as hell, we recommend watching the first video as an antidote.
- The Sims 2 has animations for most milestones in a Sim's life- including a levitating first kiss.
- Jade Empire has a well-animated scene that is suggested to be the player's first kiss, heavily implied to be Dawn Star's if she is the girl, almost outright stated to be Silk Fox's if she is, and definitely not Sky's.
- In Fragile Dreams, Seto's is stolen by Crow, who apparently thought that it's typical for friends to kiss since he read it in a book. This makes them best friends.
- Every heroine is rather romantically naive in Canvas 2 and generally has never even kissed before. Hiroki, though, is not a virgin. Of course.
- K'thonya from Earthsong's remnant (the only memory she retains thanks to teleport-induced Laser-Guided Amnesia) is of her first kiss.
- Happens in Book 0 of Flipside, between Regina and Lucient.
- Lucy and Mike both have their first kiss in Bittersweet Candy Bowl. Not at the same time, though. An extra comic shows Mike's first kiss was with Sandy.
- In The Dreamer, Bea and Alan kiss within the first pages of the comic; Bea and Ben kiss in issue #7.
- The Dreamland Chronicles Finally
- Ben and Roxy Harden in this strip of Loserz.
- In Endstone, Kyri's greatly surprises her.
- Sandra's efforts to get a decent first kiss failed miserably so far in Sandra and Woo.
- In Erstwhile, Maid Maleen and the prince kiss after she reveals the truth.
- In Sinfest, Percy's romantic first meeting concludes with this.
- In the Whateley Universe, Jade makes a big deal about her first kiss, which makes sense since she's Japanese and fourteen and immature and loves anime. Thuban, the boy she first-kisses, is still dating her.
- Across the Pacific, there's the All Grown Up! episode "Fear of Falling". Angelica is PO'd that Tommy not only had his first kiss, but that he spoiled hers as well.
- Lisa Simpson shares a first kiss with local bully Nelson Muntz.
- In "Stealing First Base", Bart kisses a girl who complains that he ruined her first kiss.
- Doug's first kiss was the subject of an entire episode where he was getting these mysterious Secret Admirer notes in his locker. He goes through a series of private mind games worrying about who it was, and eventually found out it was Beebe Bluff (Who is a nicer version of the Alpha Bitch). It turned out that she had mistaken his locker for someone else's, but she got excited and kissed him because they could switch places in a parade; Doug got to be next to his crush Patti and Beebe next to her intended target, Doug's friend Skeeter.
- Kim Possible had her first kiss with a kid named "Walter Nelson", and their braces locked. Her best friend...well Ron's first was with a CPR dummy. So you could say it was...nah, that's too easy.
- At The Emperors New School episode The Emperor's New Musical, Malina kissed Kuzco during the musical's ending. At the credits, Kuzco asked Malina if the kiss is real or not. Malina tricked him, saying that the kiss was just acting.
- An episode of Pepper Ann has the title character worrying about whether she's ready for a first kiss in a manner reminiscent of how television normally portrays anxiety over a different kind of first time.
- On Adventure Time, in "Too Young", Finn kisses Princess Bubblegum to turn her eighteen again.
- Just as their about to launch the Day of Black Sun Invasion and Aang is going to face the Fire Lord, Aang finally kisses Katara, this being his first kiss (at least onscreen, if one counts Cave of Two Lovers). Mixed with a little bit of "Shut Up" Kiss and If I Do Not Return.
- In fact, Freddie already had his first kiss in an earlier episode, but it was Handwaved as 'not counting'-- perhaps because that one was a quick kiss on the lips, and not an open-mouthed one. But that's a debate for another time and place.