This has been a much maligned category. We need toss in some more movie discussion. Lots of scifi movies to choose from. So how bout starting with Alien?
In my opinion, a classic. A perfect blend of science fiction and horror. If one likes either of those genres, than this movie scores high marks.
It's one of those movies you can still watch today and feel that its technology and setting are not "dated". Okay, not TOO dated. It's not like most old scifi where you take one look and laugh your but off (no good examples coming to mind, Logan's Run maybe, Star Trek?)
Alien also had one of the most original Aliens ever. It's creation has spawned a whole new form of alien race. Sigourney Weaver was also one of the first, if not the first, major female lead in a scifi movie. Before then, most scifi women were flakey maidens-in-distress-syndrome, large breasts, can't think, must be saved. Then Weaver came a long and kicked some Alien but. Talk about a strong, female character. (Can anyone think of a scifi movie before Alien that had a major, strong, female lead). Leah from Star Wars maybe an exception, but Luke and Han still had to save her over and over again.
Alien is a classic in my book.