In seriousness, my favorite movie would probably be either 2001: A Space Odyssey or Blade Runner. They're just two movies that I can, and have, watch over and over again, finding something new each time and enjoying it more than the last. Ten years ago, I probably would have said one of the Star Wars movies, but it's been a long time since I've watched any of them and I doubt I could watch any of them [even the really good ones] again like I used to. So, now it's 2001 or Blade Runner.