Hi Kate!
I like watching old sci-fi movies, although that kind of depends on how you define "old." I like the original Star Wars movies, but they are over 30 years old now! One "old" sci fi movie that I remember enjoying was the original "Andromeda Strain" movie from 1971. Some other really old sci-fi films I think are kind of fun are "Fantastic Voyage," "Flash Gordon" which has music by Queen, and Disney's "20,000 Leagues Under the Sea."
Kris