Battle L.A.

The most badass alien movie there is. It is up there with Predator and Independance day. The only thing different is that the aliens are ON THE GROUND and CAN ACTUALLY DIE.
The main characters are U.S. Marines, which amps up the badass meter even further.

Guy 1: Dude, did you see Battle L.A. yet?
Guy 2: No...
Guy 1: I don't know you...