Garfield acts very sweet around his sister and her boyfriend. He even confesses that he had a Disappeared Dad to Conner as a way of explaining why he wanted them back together.
After an intense night of hostage taking and anger, Jason Todd finally forgives his Bat Family for his perceived Middle Child Syndrome. He admits that he can never come back to them really, but he promises to uphold their secrets to the end, and help them in his own way.
We get more time to develop the Tim and Cassie romance, making it far more adorable and fun than its Last Minute Hookup in the show.
Batgirl forgiving Nightwing for dating Zatanna while also dating her.
Giovanni Zatara gets one night off to visit Zatanna while she's sleeping. The first time they'd seen each other in years.
Conner acts all warm towards M'gann, especially after the attack on the Watchtower.
Even in the face of the Apocalypse, Starfire still finds ways to stay happy with the rest of the Team.
M'gann projecting a montage of all the good Connor did in his 5 years of being a hero to convince Jor El to heal him.
Even though Jason's still rough around the edges, he's acting in an almost playful manner to Dick in their meetings during the Apocalypse.
The League's extreme pride in the Team for helping to expose Godfrey and still find a way to maintain their cover.
Nightwing and Batman's handling Cyborg. Both clearly understand his need for closure, and the need to confront the man who ruined his life. Yet both of them clearly are looking out for him, trying to make sure he doesn't go down the path of evil in the process.
"Confrontation" is a time for people to say their final rites before the Grand Apocalypse from Apokalips, and has some rather touching moments throughout.
Virgil suggests to Victor that being a hero is all the rage these days. As the last guy who got powers unexpectedly and was dragged into a world of heroes, nobody knows more about becoming a hero than him.
Kaldur's conversation with his father Black Manta. While neither of them are ever going to budge from their positions as hero and villain, there's clearly a deep respect between them that even being thrown in prison couldn't change.
Alfred assures to Batman that when he defeats Apokalips, then he'll be proud that the universe will be as afraid of him as the criminals of Earth are. And that he'll always see him as a son.
Nightwing helping Barbara though her injury, helping her find her joy and confidence again.
Superboy and Artemis discuss what it was/is like to love someone, and this reveals that before the reach invasion, Wally proposed to Artemis. This lost opportunity is what inspires Connor...to propose to M'gann.
The relationship between Starfire and Red X. They began as enemies. Opponents. Then after seeing his true face, Starfire begins to respect him as a warrior. Then they began coming to an understanding, and she even learns his real name.
From the battle on July 4th:
Beast Boy's change of prefixes before going into battle. Asking that his big sister come back and give him a nephew, Mrs. Martian.
It's pretty sweet to think about Cheshire's arc over the course of the show. She went from an evil lackey, to a part-time ally, to a vengeful sister, to a supportive sibling, and in the final battle, she even gets to go on her first official League mission to rescue her sister's fiancee. While her redemption arc is a bit more ambiguous, it's still pretty nice to see.
Garth and Kaldur reminiscing on their lost love, as both of them agree that they cannot lose Atlantis, for Tula's sake.
The fact that even though one used to be a villain, one just came back from the dead and one was shunned for the first year of his life, the Superfamily surprisingly gets into a groove right away, coming together to fight Doomsday.
The clash with Klarion ends up producing several sweet moments. First was Beast Boy's realization that he was the last person who could make a difference in the battle, and thus rising to the occasion to save Raven from dying.
Then there was a pseudo closure for the Dr. Fate/Zatanna story, as Nabu finally acknowledges that yes, her father did call out to her during the battle, and yes, he will acknowledge his care for her.
Volcanna's Heroic Sacrifice. Yes, you read that right. In her last moment, Volcanna saved her teammate from death after they decided to desert, and had a surprisingly touching sendoff as Barda Let Them Die Happy, promising her that she could have gotten Superboy.
Despite the obvious animosity between Aquaman and his many enemies, he's still remarkably calm about treating them like humans, whether it was discuss that King Shark ate his brother, or assuring Black Manta that they both trust Kaldur, so he will honor his escape.
The happy reunions after the battle. M'gann reuniting with her husband, Starfire's joy at their victory, Wally and Dick finally reuniting, Supergirl and Mrs. Martian burying the hatchet as sisters-in-law, Beast Boy finally getting to hug Raven, and the six veterans of the original Team having a group hug at the end.
From the epilogue
Wally and Artemis finally have their honeymoon in Paris like they wanted. Only this time, they have a daughter with them.
Dick's fondness in hoping that he and Oracle might continue to grow close together like before the dating mess up.
The founding of a 3rd team, and all the optimism put into its new members and new base.
Bart Allen finally did it. After a year and a half of saving the world and traveling to avert the Bad Future The Distant Finale reveals that thanks to his actions, his future is totally eliminated, indicating that the world in the future is safe from destruction.