* 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?]] Gullible soup?"
* Luigi humming/whistling 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 this game even when 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 [[https://www.youtube.com/watch?v=W3B0CpF8wAo "song"]] that plays while you're capturing a normal ghost is just plain weird. Just try listening to it without laughing or being incredibly confused.