Movies have long been at the forefront of space exploration, whether it's with alien encounters, time travel or just toying with way-cool technology.

So when we sat down to compile our list of the best sci-fi movies of all time, we looked all the way back to the classics ('Forbidden Planet'), to the movies that defined their times ('2001: Space Odessey') and our childhoods ('Star Wars').

It was one small step for Moviefone, one giant leap for movie lovers. Join us as we count down the 25 best sci-fi films of all time.
categories Top 25