Gundam. Looks, sounds and speaks like an evil warlord, what is his Super High School Level?... Animal Training, his current pets being 4 cute hamsters. And the hamsters are called The Four Dark Deva Lords of Destruction!
The conversation that results from Fatogami's attempts at unifying the group.
Fatogami: If we wish to live through this extraordinary ordeal, what do you think is of the utmost importance right now?
Akane: ...Of the utmost importance? You don't mean food and sleep, do you?
Komaeda monologuing at the beginning of chapter 2, only to be interrupted by someone shouting "SHUT UUUUUUUUUP!!" and a crashing sound.
Souda gets himself and Hinata invited to the girls beach party hoping to see Sonia in a bikini. Cue Sonia showing up in a wetsuit.
The group's general reaction to Ibuki Mioda's singing performance.
Souda's face specifically.
Or the fact that Hiyoko is the only one who enjoys it.
The roller coaster ride.
The fact that Souda pretty much had to be forced onto the roller coaster by the rest of the group.
Souda and Gundam's expressions during the roller coaster ride.
Sonia's reaction to RoboNidai.
Souda's reaction is pretty hilarious as well. He's a little too enthusiastic when he asks Nidai if he could take him apart so he could study him. And both times when Nidai claims he has a new ability, Souda's first question is "Is it flying?"
RoboNidai and his ability to create beverages from his eyes.
And his enthusiasm in offering Hinata a drink
Gundam calling Souda a virgin.
Sonia revealing she isn't.
And the fact that she's only disappointed because it means she can't go to an amusement park in Hell with Gundam.
Sonia Nevermind speaking like a formal princess, exactly as you'd expect...and then randomly throwing "hella", "tomfoolery", or "you betcha" into the mix or making references to outdated Japanese popular culture.
"Fat Togami"'s Free Time events, in which Togami talks in perfect seriousness about body mass indexes or deciding which meat is better than the other.
During the first trial, Komaeda reveals his intentions, leading to this gem:
Ibuki: Oh no! This guy is definitely the type who killed animals in his neighborhood when he was a kid!
Sonia: The type who watches "Friday the 13th" with a gleam in his eyes... Just like me.
One more for the count:
Akane: What's an 'aspersion'? Does it taste good?
Hiyoko: Asbestos is also excellent, you know. You should try some, later.
Hanamura's breakdown at the end of trial one; he devolves into completely unintelligible rural gibberish which somehow ends with him screaming AVRIL LAVIGNE! (As the cherry on top, Monomi - who has been translating for the other students - dutifully parrots this last line even though everyone could hear it.)
To put this one in context, Avril Lavigne is a popular Canadian singer-songwriter. She has absolutely nothing to do with Hanamura's profession as a chef; her name is just dropped out of nowhere to show how crazy Hanamura has become.
After the end of the first chapter, Komaeda goes on this really hokey spiel about hope after having led Hanamura and Togami to their deaths. Akane offers to punch him, but Hinata tells her to lay off and ignore him. Not a minute later, and...
Komaeda: You don't even remember your own talent...
Hinata: ...Owari, go ahead and punch him.
Tanaka, true to form, offers a line that's both magnificent and hysterical:
Gundam: Monobear. I will listen to your jests later, as I smoke a cigar standing over your corpse.
Later on, Akane complains about how all of the killers are getting their supplies from the same place:
Akane: The Mart, again...? That place is pretty much the one-stop-shop for all your criminal needs, huh.
In Komaeda's first Free Time event, he helps Hinata figure out his talent by suggesting some, which include Super High School Level Therapist, Amnesiac, Eccentric, and Spiky Hair.
In Chapter 4, Sonia, who hasn't eaten due to Monobear's sick game of locking them in a tower without food unless someone is murdered starts seeing her friends' faces as cake and even asks, as politely as always, if she could eat a part of them.
Sonia: Oh my, Mr. Hinata…Now that I’ve taken a closer look, your face is a Sachertorte! May I take a portion of the center? I’ll make sure to return it to you later!
Hinata: Sonia…Seriously...Get ahold of yourself…
In chapter four, the gang splits up several times to explore the new island; each time, Souda declares that he'll be going with Sonia, only for someone else to inform him that she already left with Gundam.
In chapter five, the group is debating whether or not Komaeda would have died instantaneously from his spear wound: