I. Love. This. Movie. It's amazing. Even after so many viewings that I've lost count I still laugh hard watching this movie. I quote it more than I probably should.
In college I watched this movie whenever I had a bad day - it wasn't the humor that made my day better... it was the idea that the whole world was blowing up. My aunt always knew when I was mad at the world because I was cheering on the aliens.
I've been known to watch this movie more than once in a single day. I've marathon-ed a whole weekend of just this movie. Normally I'm sick as a dog and too tired/lazy to get up and switch out the movie - but that's a minor detail.
Will Smith and Jeff Goldblum were such an unlikely pair, but it worked. Jeff is quirky... and Will is a dork. In Smith's first major motion picture he proved that he had the chops to be more than a teen demographic sitcom star. Bill Pullman was the best choice ever for a president. And Randy Quaid always plays crazy (because he IS crazy) to perfection.
Great cast, fun story, just a great sci-fi flick.