Austin Powers: International Man of Mystery: Oh my gosh. Every scene in this movie was funny, and not just funny, really funny. Although the other ones have Mini-Me, and most funny.
Borat: The funniest movie I've ever seen (again and again) isn't on this list--"Used Cars" starring Kurt Russell and Jack Warden, so I'll go with Borat.
Happy Gilmore: Adam Sandler is hilarious! This is a great film, such a heart warming comedy! Makes me laugh every time! Must watch.
Ace Ventura: Pet Detective: The movie is wild, crazy, and at some points; more than a bit moronic. Yet it has got a touch of subtle wit to it.