Just off the top of my head: Winslow's man-crush on Guybrush ("I like it when you point at the map"), LeChuck's attempt at solving an adventure game puzzle, Coronado De Cava's obsession that Guybrush has a thing going with the Voodoo Lady, Guybrush possessing the Voodoo Lady and not only enjoying her "physics" but also finding out why she "never stands up when I'm around", De Cava's crew's obsession with the rather-dead Santino (and the discovery that he was the most awesome person in the crew), Murray's political turn, two pirates squabbling over who gets to bury the treasure, De Singe's obsession with amputation, "Pirate Spunk", a spin on insult swordfighting where you have to help a manatee hook up with a bloodthirsty female, McGillicutty's "torture" technique, and of course, Murray's commentary over the end credits of Leviathan... and we're only 3/5 of the way through!
There's usually one of these right at the end of the lukewarm open. Of special note is Chapter 1's:
Guybrush: "This'll be a snap. *tries snapping* A snap. A sna- (poxed hand punches him in the face) OW!"
From episode 4, add any time Guybrush and his lawyer interact with each other. As well as any time the judge gets angry. "The defendant will stop pretending he knows how to speak Latin!"
And Episode 5, despite being the Darkest and Edgiest episode yet, has the sequence where Guybrush taunts Bugeye, just about any conversation with Galeb, and the revelation of what happened to Guybrush's corpse.
Murray. Just Murray.
Elaine charges in on Guybrush's trial while she's pox-infected and acting violent in episode 4:
Guybrush: "Plunder bunny! [...] Eeeelaine... less plunder, more bunny please."
In Episode 3, when Guybrush "kills" the clearly dead and skeletonized Santino by cutting Murray off his shoulders to intimidate the crew... and it works.
Of all the options available during the swordfight at the beginning of episode 2 of Tales Of Monkey Island, few are as satisfying as inspecting the ship's mast. Repeatedly.
"Nice cans. ...I mean, nice cans."
Having to walk LeChuck through a particularly simple puzzle. Especially if you've used the SCUMM interface of the earlier games. "Use... breath mints... yourself."
"Use... claw thingie... yourself."
Guybrush pretending to sacrifice the Pink Pajama Pierre Porcelain Power Pirate figurine at the altar in Chapter 1.
Also funny is when he does that pretend voice while dipping the figurine in a vat of ink. "Sacré bleu! Eez zis ze end of Pink... Pajama... Pierre? Glug!"
Also, Guybrush distracts De Singe on the last wind idol so he finds a way to have De Singe blast himself sky-high and onto the idol. You can even hear De Singe yelping in pain as Guybrush rotates the idol until the correct facial part-matching makes him sigh in relief.
Not to mention Guybrush's reaction if you attempt to use the weather vane like you do with the other idols.
Guybrush: Oh, I'd love to, but I'm pretty sure that De Singe doesn't have the necessary... slots.
De Singe sings while carrying out his master plan.
De Singe: Alouette, I will live forever, alouette, immortalité...
Later in the same scene:
De Singe: Whatever gave you the ridiculous idea that I'm French?
LeChuck in his speech to Elaine near the end of Chapter 5: