Somebody else already mentioned Sneakers, so I'll have to go with... Independence Day. Because Will Smith needs to make as many alien movies as humanly possible. No, seriously, this movie has everything you'd ever want - kickass actors (Bill Pullman! Jeff Goldblum!), a rockin' adventure plot (aliens! taking over the earth!), and lots of snarky dialogue. A true classic.

Clue comes a close third to ID and Sneakers, though.