A couple of very funny lines in Chapter Two, Part Two:
Saionji saying "Snitches get stitches."
Pekoyama saying "You... You don't think Nidai actually pooped anywhere around here, do you?"
Nidai's poop fixation in general certainly qualifies. ("A LITTLE HOLE WILL NOT SUFFICE!")
Two of the alibis from the second trial:
Tanaka: I was in my cottage, reading aloud to the Dark Gods, as is my custom. I remained at this task the entire evening, until they grew tired.
Koizumi: That's... weirdly adorable.
Sonia: I too was in my cottage the entire evening. I was also reading, if not to hamsters.
The entire "Titty Typhoon" exchange featuring a delighted Saionji yelling it all over the place, an exasperated Koizumi, and a thoroughly confused Hinata.
Hinata: What the hell's a titty?
Ibuki and Twogami's first shift of protecting the game, which (offscreen) dissolved into a discussion about their main interests. So Twogami told Ibuki about various kinds of meats (not unlike his talk during his free time event from the original game) and Ibuki decided to tell him all about punk rock. As in try to tell him the complete history of the genre... in thirty minutes. Even Hinata was amused by this mental image and in "Ibuki's greatest amibition" we finally get to see how her "history lesson" went.
Byakuya: “I’ve been listening very carefully, but… Mioda, you’re going too fast. I haven’t been able to understand a word you’ve been saying for about the past half hour.”
After discovering the ruins Nanami took a keen interest in them but was later ordered by Twogami to stay away from them, since (as they have an obvious gattling gun attached) they could be very dangerous. So what does Nanami do? After Byakuya is forced to take a much needed nap she not only goes back to the ruins but she tells everyone else to meet her there too.
Nanami's out of character moments after contracting despair fever are hilarious.
Particularly her flustering Tsumiki who does not understand the word own.