Ahh, some good movies listed here!
Barbarella - a young scantily clad Jane Fonda was the best part of that flick.
Soylent Green is awesome; then you'll have to check out the other Charlton Heston sci fi movies: The Planet of the Apes (origionals of course).
David Bowie was in a wacked out scifi movie in the 70's 'the man who fell to earth'.
'Logan's Run' is awesome.
'Dark City' was really great and not what you'd expect at all.
'Contact' with Jodie Foster.
What was the movie with O. J. Simpson were they faked a Mars mission?
'Sky Captain and the world of tomorrow' was an astounding movie.
'Galaxy Quest' was amusing.
'The computer wore tennis shoes'
'The Black hole'
'Escape from Witch Mountain'
'Flight of the Navigator'
'Outland' - Sean Connery?