There are a lot of bad horror movies set in space ("Jason X", anyone?). There is one reason that so many space horror movies were made, and that reason is "Alien". Released in 1979, the movie tells the story of a commercial towing spaceship, called Nostromo. The ship is carrying its seven-member crew in back to Earth in stasis. The ship's computer awakens the crew when it receives a transmission of unknown origin. This sets off a horrifying chain of events and introduces us to a legendary monster. The great cast is lead by Sigourney Weaver and the movie does a great job building suspense. This is truly a classic that you should revisit. It's also a good idea to check out the sequel "Aliens", which was directed by James Cameron.