north by northwest

off the top of my head,

12 angry men
touch of evil
rear window
it's a mad mad mad mad world
the good the bad and the ugly
singin in the rain
the gold rush
city lights
dr. strangelove

and for foreign films from before the 70s:

battleship potemkin
the man with a movie camera
the passion of joan of arc
yojimbo

pre-1970s hollywood is still way too broad a category though

and if I had to pick only one it would definitely be 12 angry men

Rosemary's Baby no contest

Night of the Hunter
M
Modern Times
The Third Man
The Trial (pretty much anything from Orson Welles' oeuvre, tbh)
Why Worry?
The Great Dictator
The Miracle of Morgan's Creek
Steamboat Bill Jr
Wait Until Dark
The Innocents (the 1961 one)
The Great Silence
Once Upon a Time in the West
My Name is Nobody

I could probably name a lot more, I'm a big fan of a lot of older films, especially silent era stuff

This.

Goldrush with DUBBING (there is a silent and a dubbed narration version and the narrated version is awesome)
The Day the Earth Stood Still (1951)
The Treasure of the Sierra Madre
39 Steps
Trouble in Paradise

(A lot of others that have been mentioned above would also make the list I tried to pick some that weren't already mentioned that I really liked).

I wont bother naming foreign films because I'd be here all day :( lol Classic Russian and Japanese movies are my favorite.

sick choice too

Lawrence of Arabia