Science Fiction:
The Day the Earth Stood Still(1951) Great sci-fi, great robot, ahead of it's time.
Forbidden Planet(1956) Robby the Robot, The ID monster, and a serious role for Leslie Nielsen.
The Beast from 20,000 Fathoms(1953) Classic Harryhausen creature feature.
Them!(1954) One of the first of the nuclear disaster films. Also, one of the best.
You must be my long lost brother. Don't forget 'Earth Versus the Flying Saucers' from Haryhausen either.