As far as older movies I like creature/sci fi movies the most. The Incredible Shrinking Man, Them!, Forbidden Plant, Creature from the Black Lagoon, The Blob, The Thing from Another World. Another one that I've been meaning to watch is Invasion of the Body Snatchers. I think I've seen most of the big ones but I'm very open to anything similar.
Other than that I've only seen the big name pre-70s movies. Dr. Strangelove, 2001: A Space Odyssey, The Wizard of Oz, It's a Wonderful Life, 12 Angry Men, The Sound of Music, Bicycle Thieves, etc