-Airplane! if you haven't seen it. Mostly timeless jokes/gags, as opposed to the celebrity, and pop culture reference crap that passes as parody nowadays.
-Tropic Thunder. I went in thinking I wouldn't like it, but ended up loving it. Especially Downey Jr.
-Annie Hall was pretty funny too if you don't mind Woody Allen. Its him in his prime.
-Not movies exactly, but any George Carlin standup show makes me bust a gut laughing ever time. Well, maybe all but one. "Life is Worth Losing" was kinda sick. Not in a good way, mind you. His last one was awesome though. He will be missed.