You know... I've never really thought about it that way, but my three favorites may be the same most watched. 2001: A Space Odyssey The Empire Strikes Back Miller's Crossing
Sometimes I'll watch Miller's Crossing with English subtitles/captions, just to take in all that insane and masterful dialogue, it truly is as if William Shakespeare had written a 1920s mob tragicomedy.
You ain't got a license to kill bookies and today I ain't sellin'. So take your flunky and dangle!