Dissidia Final Fantasy/Heartwarming

According to a report in 012 Duodecim, while Cloud was a warrior of Chaos he once saved Tifa from Sephiroth. Despite her not recognizing him, Cloud is spurred by the meeting into realizing he's on the wrong side. So he picks a fight with Chaos. Lying defeated and fading away, Cloud uses the last of his strength to tell Cosmos to protect Tifa. Cosmos is so touched by this that she promises to bring him back on her side next cycle.
The ending. They all get to go home at last. It's simple but astonishingly effective.
Kuja's Shade Impulse ending. Lamenting that the world has disowned him, he asks Zidane to erase his pointless existence, but instead he tries to help him up, with his trademark line "Do I need a reason to help someone?" while adding "Or is my help not good enough for you?" Even though Kuja refuses, it's not out of arrogance. He essentially tells Zidane to forget about him and go on with his own life as he vanishes into blue flames (the sign of redemption, as most of the villains vanished into purple flames). And yet, Zidane still promises they'll go back together eventually. Even the awkward Lip Lock does little to diminish the heartwarming.
Minor one: after defeating Chaos, all the heroes begin to fade away into pyreflies. Before vanishing, you can see what appears to be Ter ra comforting the Onion Knight.
In a side scene in Duodecim, Laguna counters Squall's assertion that there's no point in getting to know the other warriors since they'll all be going back to their own worlds anyhow:

"Listen. Even if we lived in the same world, there'd come a time when life'd pull us apart. 'S not a reason to avoid people. Even if it's someone you love more than life itself, that time'll come. There's no guarantee you'll even get to say goodbye. But before that happens, you get to be together, right? You can't just waste all that potential for a rewarding relationship!"

- Doubles as a Tear Jerker when you know that, whether he knows it or not, Laguna is speaking from experience; he lost both of the women he cared for, and didn't really get to say goodbye to either of them.
  - Just to really make you start bawling? The background music is Eyes On Me, the song the first woman he cared for wrote in honor of him.
Kain's contribution in the 12th cycle (see this game's corresponding Awesome tab for the full story), more specifically him going back to help his friends even though Golbez pointed out that he had the chance to escape his own demise. Duodecim goes to great lengths to show that, yes, Kain really is a hero, and he deeply cares about his friends.
- It's especially satisfying because at the beginning of Kain's plot arc, the audience reaction was probably "Oh, Kain is a traitor, yawn, we saw that happening already".
At the end of the Warrior of Light's story, when all the Warriors of Cosmos are gathered, the first thing he asks is if everyone's all right. He doesn't ask about the crystals, but about their well being. It's a small touch, but it works.
Prishe's story in Dissidia 012 Duodecim is short but very sweet and very pivotal to the story! Personally I think her best scenes when she gives the Warrior a speech about what it is to be a person. They are just so cute together! (not in the romantic way)
Speaking of the Warrior of Light, the fact that Cosmos sacrifices herself to save him is very endearing. Especially when you consider that when they first met in Duodecim she hesitated at the idea of makeing him one of her warriors. Let the Warrior of Light/Cosmos Shipping begin!
A short one from Duodecim. Gilgamesh's quote when you're playing as Terra is one of these. The Hot-Blooded lug is flirting with most every female in the game. Terra's one of the few exceptions; he asks her what's wrong, and if she wants to talk. Equally funny and heartwarming.