In the sequence where Guybrush fakes his death a second time to get buried in the Goodsoup crypt, hotel manager Griswold Goodsoup offers this gem:
Griswold: Oh, dear! He's had a sudden and completely unexpected relapse of death!
"You fool! You've given cheese to a lactose-intolerant volcano god!"
On that note, Lemonhead in general. "Shut up. Or I'll eat you."
Guybrush: Did I say "cannibal?" I, I meant to say... err, "cannon... ball." I want to be a cannon ball. BOOOOOMM!
Lemonhead: ...You're not quite stable, are you?
Similarly, after the "human sacrifice" to the volcano god (which is actually a dummy made out of fruit), complete with dramatic ritual-saying and rope-cutting, the cannibals stand around the volcano's edge and toast marshmallows.
The "terrifying" shape of Skull Island.
Lost Welshman: Well, ya see... ya gotta squint and sorta turn your head and... Ooooooooh! It's just SO scary!
Guybrush: If you squint and turn your head it looks like a bunny.
Asking LeChuck what the real secret of Monkey Island is.
Stan's triumphant return. Especially if you've played the preceding games.