Focusing on comedy, here are some of the funniest scenes I can remember.
The umpire scene in The Naked Gun. I cried I was laughing so hard.
"Hey, it's Enrico Polotzo!"
The mental hospital scene in Ace Ventura. When Jim Carrey was doing the TD dance with all the patients dancing around him, I lost it.
Baseketball..the entire scene at Brittany's house.
"C**k. Beer?"
"Man, this place looks liek a Dockers commercial."
"Oh I am so jelaous of you."
"No, it's not like HORSE!"
Good Morning Vietnam. Any time Dickerson is chewing out Cronauer.
Dickerson: This is not military issue, airman. What sort of uniform is that?
Adrian Cronauer: Cretan camouflage sir. If you want to blend in with a bunch of drunken Greeks there's nothing better.
Sgt. Major Dickerson: [Pointing to his rank insignia] What does three up and three down mean to you, airman?
Adrian Cronauer: End of an inning?