The end of first season: Lelouch and C.C. trigger a trap that links their minds, making them see events from C.C.'s multi-century lifespan, including several painful and torturous "deaths". A despondent C.C. says that she's been alive for so long, she's forgotten who her loved ones are, and even what it means to be human. Lelouch replies: "You're wrong. You're not alone, because I'm here. We made a contract, remember? If the world considers you a witch, then that makes me a warlock." If anything breaks the constant comparisons between Lelouch and Light Yagami into tiny pieces, this scene should be it.
When C.C. kisses Lelouch in the first season finale.
A good ways into R2 Turn 7, Lelouch's musings on "glass". Epic fuzz.
Just beforehand, where it was revealed that the student council all decided not to go to the school trip mentioned earlier, but instead stay behind and light fireworks in the hope that Lelouch would join them.
At the end of episode 8 of R2, when Lelouch takes off the Zero mask in front of Sayoko, and she just smiles.
The interactions between Lelouch and mindwiped C.C.
There's this one scene where Suzaku tries to clear the table but Lelouch does it instead, stating that Suzaku was a guest and that it was their turn to serve him. This is only one in many moments showing how close the two are to each other.
When Kallen is captured by Li Xingke in R2, Lelouch visibly panics and swears to her that he'll save her no matter what, even though doing so meant jeopardizing a vital mission.
Rolo's final fight and death may be the most badass, heartbreaking, or utterly sweet thing in the entire series. Or all three.
The real kicker is that it's implied that, in the end, Lelouch actually came to care about Rolo on some level, as evidenced by his inclusion of Rolo's name in the list of people and things important to him that he'd lost.
This quote about that moment is also all three. Awesome because Lelouch is letting Rolo die happy, Tearjerker because Rolo is in denial about Lelouch hating him, and Heartwarming because Lelouch is serious when he says it and has truly accepted Rolo as his familly.
Lelouch: Rolo, why did you save me, after all I've done to you? Rolo: Because, you're a liar, big brother. It was a lie wasn't it? What you said about trying to kill me and about hating me and all of that. Lelouch: Of course, and you saw right trough me didn't you? Just what I'd expect from my little brother. Rolo: That's right, I thought so. 'Cause I know who you really are inside your heart. I know everything about you, big brother. (Closes his eyes) Lelouch: (Puts Rolo's locket and cellphone in his hand) … Yes, you got it right. Your big brother's just a liar.
Then Lelouch hangs Rolo's locket over his grave. The locket he had meant to give to Nunally. One would think he would commemorate it to his (as far as he knows) dead sister, but instead he gives it to his dead brother.
C.C., without her memory. Cut finger scene. Episode 16.
When Lelouch, in R2, is revealed by Schneizel, he chooses to play the role in order to save Kallen, who still believes in him to this point. As she walks away, he utters "live, Kallen"
Episode 24 of R2, Cornelia and Guilford finally reuniting. Who cares that the series will almost certainly never explain how Guilford survived a nuclear explosion of all things, it was nice to see something GOOD happen to the guy for once.
Cornelia: You still call me that?
The "Lelouch, don't you hate me?" convo from 24. Too bad about the Moment Killer.
The final episode where Nunnally (along with many of his former allies who thought they were going to be executed) cries (more like utterly breaks down) for Lelouch, realizing his sacrifice, and saying that he "was the only thing she needed in this world" to be happy... as the crowd around her goes wild cheering for Zero(zaku), the man who had just assassinated Lelouch
It's also heartwarming because in cheering the man for killing Lelouch, cheering for Zero, they are actually unwittingly cheering for Lelouch himself, giving him quite the touching send off instead of the intended malevolent one.
Despite the Tear Jerker, there's something strangely heartwarming about Lelouch and Suzaku's final conversation and flashback. The fact that after everything their friendship has gone through, they still have such faith in one another...
Yes, and Lelouch gently stroking Suzaku's face/mask and tenderly hugging the man who just stabbed him. After everything the two of them have been through, that final moment of friendship was incredibly powerful.
Kallen finally having a normal school life (even wearing her hair the way she likes it) with her biological mother in a free Japan, Nunnally and Suzaku (as Zero) working together for peace, Jeremiah and Anya in the orange farm, and C.C Walking the Earth, having outgrown her death wish thanks to the time she spent with Lelouch(and possibly continuing to spend eternity with the man)...
Euphie and Suzaku are just utterly adorable in general. No wonder how it ended was such a gut-punch.
A Picture Drama. It's just... The surviving student council member get a chance to reminisce, visited by Zerozaku and Nunnally, while Villetta and Sayoko look outside at them from the windows, discussing how things are finally looking up. Then the real moment: Jeremiah and Anya set off a bunch of fireworks, as per Lelouch's final request, so that everyone can enjoy them together one last time. After some parting words from Suzaku and a mention by the council that Rolo and Shirley are watching this with them, the final chronological scene for the Code Geass Anime canon is this◊. In one last Crowning Moment of Heartwarming it was shown, that in some way, even Lelouchgot his happy ending. It's also a callback to the "musings on glass" mentioned above, as well as to several other recurring elements: Anya happy at finally having her memories "within her", Jeremiah's loyalty and carrying out his master's last wish, Villetta and Ohgi's wedding, as well as more info on how they got engaged, and even Nina is shown to still be doing a lot better.
In Turn 6 of R2, Suzaku attempts to see if Lelouch has regained his memories through phoning Nunnally, whose become the new Viceroy by this point and having Lelouch speak to her. Not only does Rolo use his Geass to buy Lelouch time to explain to his sister what he's about to do, but what Lelouch says to Nunnally ought to have a place here:
Lelouch: I'm going to comfort you. I swear it. So until then...until then...I love you, Nunnally!
The fact that he then proceeds to speak to her as though she's a stranger in order to throw Suzaku off is a mild Tear Jerker, to boot.
From R1, before the Battle of Narita.
Lelouch: C.C. I don't know why snow is white...but I do know that snow is beautiful.
R2 Turn 9 Li interupting the wedding. As he's fighting guards he wonders if Tianzi remembers the pinky promise they made. She waves her arm in the pinky position and shouts his name. there is no more doubt in my heart! She opens her arms and Li rushes to her. Every other relationship has so much baggage, the pure loyalty and trust between them pulls the heart strings.
A small one from R2 Turn 24: Villetta tries to mask her concern for Ohgi and the Britannian soldier she's having a conversation with turns to her and says "I don't mind". Heartbreakingly, she and Ohgi were responsible for the Ship Sinking between Lelouch and Kallen, Lelouch's final falling astray, and thusly, the predicament at hand, the Zero Requiem.
R2 episode 12 gives us Cupid Day. Shirley gets perhaps the most uninterrupted time with Lelouch of the whole series that isn't gut-wrenchingly sad.
Episode 13 of R2 (even though it ended horribly), where Shirley with all her pre-geass memories back falls almost to her death off a building. Lelouch grabs her by the hand, and Suzaku is holding onto Lelouch's legs. The whole thing is heartwarming in that it shows not only a touching moment of Lulu and Shirley, but also Suzaku and Lelouch working together.
Pretty much any scene that shows Nunally, Suzaku, and Lelouch as children is a mix between this and Tear Jerker, seeing how it all ended up.
The scene where Lelouch plots for Suzaku to become Nunally's Knight, before discovering he and Suzaku are enemies. Yes, it is a bit creepy that Lelouch plans out the lives of those closest to him like chess pieces, but this reveals how much he trusts Suzaku and also how he hopes that Nunally will give Suzaku a reason to live. This is also the last time we see all three of them happy together before Lelouch figures out Suzaku is the Lancelot's pilot and everything goes to hell. Of course, in the end, Lelouch actually got his wish since Suzaku DOES end up protecting Nunally and finds the will to live.
When the Black Knights are discussing who Empress Tianzi should be married off to for political purposes, and right in the middle of the dispute, Tamaki shows up to interrupt the whole thing. No, that's not the awesome part. It starts when Zero (after dodging the other Knights and going off with Tamaki) gets a phone call...from Shirley. Zero (or rather, Lelouch) then tells her about a situation wherein a family is suffering "family politics" regarding a marriage, to which Shirley suggests the girl in question should choose whatever her heart wants. After hanging up, Zero comes back and in grand Zero fashion tells Tianzi that the decision of whom she marries is hers to make alone. What made it awesome was that the whole thing was technically caused by Shirley, who just unknowingly pulled a CMOH (and arguably a CMOA as well) for the Empress of China without even realizing it using The Power of Love!
In the outros, we get lots of official art, some of which are quite heartwarming. The big ones were a younger and very happy-looking Lloyd and Rahskata with what looks like a younger Cecile, and a pint-sized Nunnally wearing her mom's ridiculous hat.
A minor moment, but when Suzaku is knighted, no one except for Lloyd claps initally, then General Darlton starts clapping, this is heartwarming because Darlton is one of the few high ranked Britannians who ignores the fact that he's a honorary britanian and sees him for the talented soldier that he is.
A very small one, but in R2 when Lelouch and the Emperor are discussing instrumentality, Chuck refers to Euphemia by her affectionate nickname "Euphy". Considering that only her close siblings and Suzaku call her that, it would seem that Chuck does care about his daughter just a little bit, which is heartwarming given his usual attitude towards his children.
Even though the episode was utterly gut-wrenching, Shirley's flashback to when she was a little girl telling her dad that she would be his wife someday was incredibly sweet.
During the bit where C.C is about to surrender her Geass to Charles and finally die, Lelouch says that if she truly wants to die, she should go to it smiling. He then promises to give her that smile. The fact that he manages to make her postpone fulfilling the wish she has had for centuries would be great enough on its own, but it's even better that by that point he's stopped trying to talk her out of it, showing he respects her decision even if he doesn't understand it, and just wants her to be happy when she achieves it. Yet another one of the series' HeartwarmingTearjerkers.
Every time Zero!Lelouch is having a phone conversation with anyone of student council while... well, being Zero is one. Especially after Rolo`s death when Lelouch tells Rivalz that he probably won`t be able to fulfil his promise about fireworks... well, that one is more of a TearJerker, but counts as Heartwarming as well.
When Emperor Lelouch captures Nina, he remembers to tell his soldiers to let Rivalz go free. Might not be the MOST heartwarming moment, but it was nice that after everything that happened Lelouch still remembered the guy.
In the final picture drama, the Student Coucil's memories have been restored. They know Rolo wasn't really Lelouch's brother but they still care about him and miss him.
Lelouch forgiving Rolo after his Heroic Sacrifice, he even buries his corpse in a grave he dug with his own hands so he can rest in peace.
When Kaguya insists that she shall be Zero's wife, calling herself a goddess of victory, Lelouch politely declines, stating that "I have already made a contract with a witch. I have no room for deities." His relationship with C.C. feels like a marriage, all of the sudden.