Carl explaining to Rick that he still loves his dad, even after everything they've been to and all the terrible things they've both been forced to do.
Glenn and Maggie's wedding, presided not by a preacher, but the most spiritual member of the community. No invitations, since they just assumed everyone would come. Nothing but a speech, custom-made wedding vows, and a kiss. It shows that even after the apocalypse, with the worst of human nature surfacing, love still finds a way.
In the No Way Out arc, Rick is holding of the zombies alone so that Carl has a chance. He's being overwhelmed. Cut to each of the members of the group seeing him fighting alone, and each one of them going out to help fight them. They win. In a series devoid of optimism, this also doubles as a Crowning Moment of Awesome.
Rick forgiving Nicholas after his failed mutiny, making him see that everyone needs to work together to survive rather than killing him, despite admitting later that he really wanted to.
For the TV show:
Rick reuniting with his family.
The Mexican 'gangsters' turning a retirement home into a fortress to protect the patients.
"Cherokee Rose": Daryl gives Carol a flower of the same name as the episode. He tells her a story of what the flower means, surprisingly sweet coming from a guy like him.
Daryl: "I'm not fool enough to believe that there are any flowers blooming for my brother, but I believe that this one bloomed for your little girl."
Carol telling Daryl he's a valuable member of the team and a good man, after Daryl had been hallucinating his brother telling him no one appreciated him.
"Today, you did more for my little girl than her own daddy ever did for her in her whole life."
Rick seems to abandon Shane to certain death after they have a brutal fight. Then it turns out he was just going to get a car to save him, and tells Shane that whatever has happened between them, they need to work together now.
Hershel giving Glenn his watch, which has been passed down from father to father in his generation. Especially heartwarming given that Hershel was VERY uncomfortable with Glenn's relationship with Maggie at first.
With Dale arguing as the sole voice for saving not just their prisoner's life, but their own humanity, he is able to win over Andrea, who to this point had seemed the most solidly in Shane's camp, and the person Dale cared about most in the group. And later, when Rick is unable to carry out the execution, she looks elated at being able to give Dale the news. Unfortunately, by that point it was too late.
AMC was holding a live vote as to what to do with Randall, and over the course of the episode Dale actually won a lot of real life viewers over.
Lori apologising to Shane for the pain she's caused him, and thanking him for helping her and Carl in the early days.
Andrea and Glenn's moment in Dale's SUV, with Andrea tossing the keys to Glenn and consoling Glenn as he thinks he let Dale down.
Everyone reuniting at the highway after the farm is overrun.
Glenn telling Maggie he loved her. Awkward but sweet.
For the Video Game:
Most of Lee's interactions with Clementine, but the scene where he bandages a cut on her finger stands out as a bonding moment.
Being loyal to Kenny leads to him adding after he saves you that No One Gets Left Behind, "especially a good friend."