Kurono trying to avoid thinking Emo thoughts to stop Robo Rock Lee from killing him
Kurono: Think non Emo thoughts...Think non Emo thoughts....(Fantasies about chaining up Kishimoto) HEH! The most non emo thought imaginable!
Robo Rock Lee: EMO SIGNAL LOST!
Kurono: (Sees Kishimoto's boobs censored with a woman with a Hitler Mustache) Oh goddamn it Quadruple A! You're the cause of all my pain and suffering!
Robo Rock Lee: EMO SIGNAL REGAINED! PREPARING TERMINATION!
The Thomas Aquinas debate as Nishi is brutally killed in episode 10. Also, all 3 "happy thought" songs later on in the episode, especially Katou's Star Trek: The Next Generation-themed one.
"Keiii Kurono! Keiii Kurono! I kicked all... their asses... and fucked all... their moms!"
The entirety of the red haired thug trying to threaten a rival gang with his Gantz gun. Culminating in....
NOTE: THE RED HEADED STEPCHILD NEVER RECEIVED A FUNERAL.
The following bit from the finale:
Hojo: Who are you to decide that [Sakuraoka]'s a main character and I'm not? Kurono: Well, I've got a clean driving record, I was student of the week that one time, and oh yeah, I'm the guy who just made a fifty foot monster his bitch!