Your favorite movie? I'm looking for some old movies (1930's-1940's) to enjoy...?

I figured if anyone could recommend me some decent classics, who better than people who may have grown up watching these types of movies? I'm looking for some decent movies from the '30's or the 40's (or even the early '50's) to enjoy, something beyond "Gone With the... show more I figured if anyone could recommend me some decent classics, who better than people who may have grown up watching these types of movies? I'm looking for some decent movies from the '30's or the 40's (or even the early '50's) to enjoy, something beyond "Gone With the Wind"/"Citizen Kane"/Casablanca".
I'd especially like to watch something with Bette Davis, Jean Harlow or Clark Gable but I'm open to anything from that are.
Can anyone recommend two or three of these movies and why they're enjoyable without giving away too much of the plot?

Thanks to anyone who takes the time to answer, and 10 points to the best suggestions. :)
Update: **should say "...anything from that era.".
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