The Incredibles, hands-down. A sly look at real family issues set against a fantastic backdrop. I love everything about that movie.
Jurassic Park is a close runner-up. There have only ever been two movies during which I had such a visceral reaction to the effects that I got instantly teary-eyed: Jurassic Park and Hitchhiker's Guide to the Galaxy. Jurassic Park totally captivated me, and I still watch it from time to time.