Since Barnes already shared a scene from Top Secret and I don't really have much of an opinion beyond sporadically funny, I'll move ahead.
They Livehttp://www.youtube.com/v/7Lwlx3GnLGsBet you thought I was going to show the fight didn't you. It's a fun scene, but to me, this is the heart of the movie. Though this movie didn't make it anywhere near my list, I really enjoy this movie. It's kind of a ballsy poke at Reagan's materialistic America and it still works today. If you see it as an action movie, you might be disappointed because it really takes a while to get to that, but if you're looking for fun (though not subtle) sci-fi satire, you are in the right place. Though he never really had any big hits in the era, the 80's were a great time creatively for Carpenter, though I think we'll be getting to more of that soon.
EDIT: Oh, and though it is rather different, I also recommend the short story it was based on,
8 AM in the Morning. I'd like to see it made into a movie again. I think because of the nature of the story, there's a ton of different ways to tell it.