* Luigi looking at the bright, cheery, illustration of the mansion on his map... [[VeryFalseAdvertising then seeing the real thing]].
* The EasterEgg at the Bottom of the Well. [[spoiler:"Hey Luigi! [[WhatTheHellPlayer What's the]] [[ContinueYourMissionDammit hold up]]?"]]
* King Boo taunting Mario gets pretty funny when he says the following line...
--> "[[LampshadeHanging What do they feed you Mario brothers anyway...]] Gullible soup?"
* Luigi humming (if the room is darkened)/whistling (once it's lit up) the background music.
* King Boo freaking out over Luigi, then realizing he ISN'T Mario.
* Running Mario through the ghost portrait machine in reverse at the end. [[TheChewToy Poor guy can't catch a break in this game even when he's saved, can he?]]
* What happens when you try to open a fake door.
* This excerpt from the telephone room:
--> '''[[spoiler:Toad]]:''' ...He-Hello? ...May I ask who is speaking...please??
--> '''Luigi:''' It's Bowser!!
--> '''[[spoiler:Toad]]:''' Eeeek!! ''(hangs up)''
* Many of the Boo [[IncrediblyLamePun puns.]] Actually, many of the things the Boos say in general.
* The... *Ahem* [[https://www.youtube.com/watch?v=W3B0CpF8wAo "song"]] that plays while you're capturing a normal ghost is just plain weird. [[StylisticSuck It's so terrible and chaotic, you can't help but laugh]].
* Anytime you shine your torch at a ghost and start sucking away, the ghost will let out a - hilarious to watch - OhCrap reaction. While just about every ghost will react in their own way, the highlights have to be the grabbing ghosts, Mr. Bones and especially Shivers the Wandering Butler. [[note]] for the record, as soon as you shine light on him and start sucking him up, he lets out a scream that sounds a lot like the scream [[WesternAnimation/SpongeBobSquarePants Squidward makes]] [[MemeticMutation when someone appears in front of him just as he is taking a bath!]][[/note]]