‘The Day the Earth Stood Still’, ‘This Island Earth’, ‘Earth vs. The Flying Saucers’, and of course - ‘The Attack of The 50Ft. Woman’.
So many other classics.
Forbidden Planet
Invaders from Mars—the original version
"Attack Of The 50' Woman" was fun also, with some risque undertones for the time, although the 50' woman was technically not an alien, she was an earth chick who got irradiated by an alien "satellite"...
Anyway This Island Earth was maybe my all time favorite... I must have seen it when I was in about the 5th grade because I noticed that Faith Domergue's spacesuit seemed most flattering in an unusual way...
Also I was impressed with how Exeter turned out to be such a cool guy in the end, especially considering he was, you know... an alien and all that...