The Last Picture Show.Ones I've seen are in bold print. That post has 132 comments.
The Passion of Joan of Arc.
Wings of Desire
The Best Years of Our Lives.
Aguirre, the Wrath of God.
Make Way for Tomorrow (1937).
Tokyo Story, Late Spring, Early Spring, and Late Autumn.
Lawrence of Arabia.
On the Waterfront.
The Wizard of Oz.
The Godfather Parts I and II.
Y Tu Mama Tambien.
PZ Myers offers a list of 5 movies that made him happy:
ZardozI've only seen one from his list. His post has 296 comments.
The Incredible Shrinking Man
Children of the Damned
Attack of the Monsters
There are lots of movie suggestions in the comments to both posts.
My list of 5 films that made a lasting impression on me:
A Funny Thing Happened on the Way to the ForumOf course, if I were to make a list tomorrow it'd be completely different.
Carnival of Souls