Shame, shame, SHAME on all of you forgetting the Godzilla movies!! Godzilla vs. The Smog Monster was the best, ir you didn't know. Other great "vintage" sci-fi movies:

Westworld
20,000 Leagues Under The Sea
Colossus: The Forbin Project
Slaughterhouse Five
Soylent Green
Island of Dr. Moreau
The Invisible Man