Robinjakarta wisely mentions High Noon. One of those films I only saw for the first time a few years ago, and what a beauty.
Same with The Entertainer.
I think I would like to add to my list Wages of Fear. And When a Woman Ascends the Stairs.
These are the ones that spring to mind today:
A Separation
The Conversation
Psycho
Toni Erdmann
The Lives of Others
Evil Dead 2
Being There
The Life and Death of Colonel Blimp
Chinatown
The Third Man
Sideways
Once Upon a Time in the West