The "Conversion" sidequest. Rosch acts like Sonja has a carving knife in her hand every time you find a Core Part:
Sonja: Oh! Core Parts! Now I can strengthen Rosch's Gauntlet! Are you ready, Rosch? Rosch: (!) H-Hey! What are you trying to do!? I don't like that look in your eyes... Sonja: ("music note" emote) Heh... Don't worry. It won't hurt! Rosch: Er, Sonja... Calm down. Let's talk this over... Sonja: No! (screen fades to black; sounds of working and battle) Sonja: You look quite dashing, Rosch. Rosch: ("grumble" emote) I thought I was going to die... Sonja: If you find any more parts, you know where to bring them! Rosch: Ugh... Please don't find any more parts. Sonja: ...What was that, Rosch? Rosch: (shouting)I just said I'm so reli...Er, no. I'm so re--Um, let's go, Stocke!I can't wait to test out all the new powers of my Gauntlet!
During the Fleeting Peace bad ending:
Trying to get past the guards in Gran Plain before stealing Kiel's sword dancing moves. Highlights include Stocke being grovellingly polite, Raynie and Marco both being vastly amused by this, and Stocke having a very bad attitude about the whole thing.
The Technique Scroll sidequest, and the soldier's exponential loss of dignity. Especially:
Raynie: ...Are you hiding something? Soldier: N-No, nothing at all! Stocke: He probably just pawned the scrolls for money, but when he came back, they'd already been sold. Am I right? Soldier: (!) H-How'd you know!? Stocke: Just a wild guess. I didn't think I'd be right.
Pretty much any time Stocke gets snarky, actually.
When talking to Garland in the sort of circumstances where you generally don't want to sass the king:
Garland: That was a joke. You were supposed to laugh. Stocke: ...Then maybe you should tell better jokes.
Stocke: You're actually kind of popular. ...I have to admit, I didn't see that coming.
In the "A Knight's End" bad end, he gets some revenge for Lippti and Teo's constant refusal to tell him things:
Teo: But, Stocke... I don't understand what happened to cause these events. Could you explain to me what that was all about? Stocke: If you can't see it, you're not ready. You'll understand it when the time comes. Teo: ...... Teo: Ha! You beat me with style!
Right in the middle of the massive Tear Jerker that is the True Ending, while listing the reasons he wants to go back:
When Count Selvan is talking to Dias after Queen Protea's decision to torchGranorg. It's the utterly deadpan delivery that sells this.
Selvan: Now, if you'll excuse me, I must go set my own city on fire.
When it's gotten out that Hugo has been faking Noah's proclamations and they've been chased out of Granorg by the good guys, Selvan gives Hugo a really sarcastic "The Reason You Suck" Speech, of which the best part is this: (Note: best read entirely in Sarcasm Mode)
Selvan: Perhaps I should take a moment to offer a prayer for Noah's continued "graces!" (gets down on one knee) Almighty, all-seeing, Grand Prophet Noah! If it is your will, grant me the strength to exterminate these heathens and infidels! (stands up again) ...Am I doing it right?