The 1950s was a golden age for science fiction, good and bad.
Here are three goodies:
“The Thing From Another World” aka “The Thing”.

A group of scientists find an alien frozen in the ice at the North Pole. (1951) Don’t go for the re-make.
“The Invasion Of The Body Snatchers”

Mysterious pods appear from space and grow duplicate humans. (1956) Don’t go for the re-make.
“Forbidden Planet”

A group of astronauts visit the planet Altair IV to find out what has happened to the previous expedition to the planet. (1956)
This is a curiously sterile film, but looks great on the big screen.