What the hell, I'll pick a few particular good ones, in no order:
DUCK SOUP: The Marx Brothers in ultimate anarchic mode. Never fails to bring a smile.
THE WIZARD OF OZ: Dust-bowl bleakness(save for "Over The Rainbow")gives way to Technicolor dreams, then back to the bleakness and the unresolved fate of Toto(poor dog--you know Miss Gulch had him 'destroyed,' the wicked bitch of Kansas!).
CASABLANCA: Great Bogart/Bergman chemistry, virtually all the dialogue is memorable, and for pure B&W entertainment, can't be beat.
THE BIG SLEEP: Bogart as Phil Marlowe, a great example of cynical, suggestive filmmaking far ahead of its time.
THE SEARCHERS: If you gotta make a western, this is how to do it.
THE BRIDGE ON THE RIVER KWAI: If you gotta make a war movie, this is how to do it.
ThE HIDDEN FORTRESS: If you gotta make an adventure(that inspired STAR WARS), this is how to do it.
A HARD DAY'S NIGHT: If you gotta make a comedy/musical, this is how to do it.
A SHOT IN THE DARK: If you gotta make a comedy, this is how to do it.
KOYAANISATSI: Images and music, nothing else. And nothing else quite like it.
BLUE VELVET: Modern mix of noir and the bizarre; "In dreams, I walk, with you...."
ED
When remixing vintage tapes, imagine you are back in the time those recordings were made, and mix accordingly. forget Today's Sound Sensibilities....