Writer's Block: Space Wars
Serenity! Aha, based on the best series, Firefly.
Second is the new Star Trek movie, only the latest one.
I'm not a sci-fi fan, alien movies make me laugh and then I lose interest. There have been a few gems, Stargate (not exactly in space but not in this world either) Star Wars (come to the dark side - we have cookies) Independance Day (still not entirely in space but still a classic) and lets not forget the string of sci-fi horrors that didn't need a feasible plot, because it's the future and it's deep space. The rules were jettisoned out of the airlock before they reached orbit.
There is an interesting sounding movie coming soon, Avatar. All star cast, James Cameron, blue aliens, inter-galactic exploitation. Be still my beating heart.