There's probably others that I'm not aware of, but in addition to being an amazing movie, it's the only black and white movie I know of where the acting is natural rather than looking like someone putting on a performance.

I watched it for the first time last night. If I didn't recognize some of the actors, you could have convinced me that it was made this decade

I love the serious thriller take on the same book, the film Fail-Safe (1964). Directed by Sidney Lumet, starring Henry Fonda. No idea why this film isn't better known, if only from being compared to Dr Strangelove.