From iTunes right?
haha The Princess Bride...
I was about to recommend Airplane! too...
oooh another really funny one is 'The Producers' if you haven't seen it.
I assume you've seen all the Monty Python movies right? If for some reason you haven't, definitely watch Monty Python and the Holy Grail. Life of Brian is really good too, as well as all the others.
The Jerk. Definitely a good one. Caddyshack.
I'm sure I'll think of more.
Yep. National Lampoon's Vacation. Classic.
Zoolander is hilarious in a totally random way. I loved it.