If you are interested in sci-fi (not the Star Wars kind) movies, you will really like Donnie Darko. I watched it recently and it was definitely a great feature film. It does have a confusing storyline, but it gives a very interesting theory about tangent universes and timelines.

If you don’t want to watch the movie, I still recommend Wikipedia’s entry on Donnie Darko. In the plot synopsis is a pretty detailed description of that theory. (Don’t read it if you plan on watching the movie.)