I know Don through poker, but it turns out he’s a distant cousin. Anyway here’s his list and comments (and the thing was played by James Arness, better known as Matt Dillon in the 50’s horse opera):

I put these on my Netflix queue. I believe I saw The Thing years ago. Does Peter Arnes play the thing? My list is very similar to yours with some personal favorites added.

The Day the Earth Stood Still, 1951
Forbidden Planet, 1956
2001: A Space Odyssey, 1968
Star Trek II – The Wrath of Khan, 1982

Invasion of the Body Snatchers, 1956
The War of the Worlds, 1953

Frankenstein, 1931
The Incredible Shrinking Man, 1957
A Clockwork Orange, 1971
The Time Machine, 1960

The Man Who Fell to Earth, 1976
Starman, 1984

Enemy Mine, 1985
The Terminator, 1984

Some personal favorites:
Twelve Monkeys
Outland
Star Wars IV and V
Robinson Caruso on Mars
The Fifth Element
Dark City
The Matrix

More to come…