Right before the Shadow Army's attack on Crossroad Keep, Ammon Jerro returns to his granddaughter Shandra's farm in search of some magic items he left there. You arrive just in time to see him ambushed by a Pit Fiend who he had imprisoned in his Haven, who mocks him for his Accidental Murder of Shandra before attacking. After you both defeat the Devil, Ammon starts berating you, saying he didn't need any help. You and him then start going back and forth in an argument, with you trying to convince him that what he did before joining you was wrong, and him trying to justify it. Finally, Ammon demands to know what Shandra saw in you, since all her troubles were technically indirectly caused by you. If your influence with Shandra was high, you then tell him exactly what she saw in you. Taken aback by this, Ammon finally realizes that his methods, while well intentioned, ended up hurting the world he had sought to protect, but most of all, it hurt himself. He falls to his knees and solemnly calls out to Shandra's spirit, apologizing for his actions and begging forgiveness. As if on cue, a flash of light reveals a magical pendent that belonged to Shandra, which Ammon then takes. This final conversation cinches the whole scene.
Knight Captain: Well done. Are you still going to find those items you spoke of?
Ammon: ...No. This...this is all that I need.
If your influence with your party members are high, then seeing them, one by one, refusing to betray you during the fight against Black Garius. Special mention goes to Neeshka, who resists Mind Rape to stay loyal, and Ammon Jerro, who proudly states that he's learned from you, and that he will enjoy killing Garius for insulting Shandra.
Torio will during the trial attemt to make Shandra witness against you. If you have high enough influence with her, she defends you insstead and feels entirerly disgusted by Torio's manipulations.
Also counting as a moment of awesome, Khelgar's epic rant against the injustice of the Ember Trial really shows how much he cares for both his leader and the party as a whole.
The entire Trial By Combat bit, from companions showing up one by one during your vigil to Grobnar's song, to the people cheering in the stands. The kicker is that if you choose to save the imps from their crates, even they show up in the stands. Yes, the creatures who are essentially made of evil and mischief abandon their torment of the Blacklake populace just to cheer you on.
Late in the game, even after you and Khelgar go through an entire Fire Giant tribe and a Red Dragon to get back the Ironfist Treasure, Khelgar's old clanleader will still treat him like crap over having abandoned them. Cue the other Ironfist Dwarves (including one who had also lambasted Khelgar in his earlier sidequest) one by one coming and sticking up for Khelgar and calling out the clanleader for being an Ungrateful Bastard.
And Neverwinter Nights 2 has Neeshka. If you've treated her well, she'll refuse to turn on you even under torture. And when she's bound by her demonic blood and magic to do so anyway, and you tell her you need her:
Neeshka: "I...I can't do it. I won't do it! By the hells, I'm not going to turn on the one person who showed me kindness! And if it costs me my life, so be it."
Getting Elanee to stand with you against the corrupted druid circle of the Mere leads to some pretty good ones too.
Mask Of the Betrayer
After Okku joins you, one of the conversations with him has him angrily chastising you for devouring the spirit of one of his closest friends. You have the option of responding by agreeing that it was unforgivable, and allow Okku to name his punishment. Okku is surprised by this act of selflessness, and gains a hefty influence boost.
Similarly, when Okku is being threatened by a group of spirit bears over how his attempt to contain the Spirit Eater doomed his race, sticking up for him by demanding to know what they would have done in his situation yields a similar outcome.
Healing the Woodman. In one shining moment you prove that not only does the Wall's hunger not control you, it's got nothing on you. Especially satisfying when everyone lines up to apologize for ever suspecting you and outright gush over you.
When you enter the Dreamscape in Act III, you're immediately thrown into a battle in a dream-Crossroad Keep...with your dream-companions fighting beside you. Even Bishop. Even Qara. Even Sand and Neeshka, if they betrayed you instead. Even Shandra will be there. Just seeing everyone back together again, fighting loyally to save you, even if it's just a dream, made this troper tear up a little. And then, if you talk to them afterwards, they'll greet you with a cheerful but in-character line that just takes you back to the days of the original campaign.
The part that comes next has you fighting in West Harbor, alongside your foster father, both of your childhood friends, Cormick, and Lorne.