Another Top 100 list from a self-appointed authority: the American Film Institute's choices for the best films of all time. To see their PDF list, use the bugmenot credentials moviebuff100/hundred or check the Washington Post's copy.

I've seen 37 of these titles; three of them were assigned viewing in school ("Apocalypse Now," "Mr. Smith Goes to Washington," and "To Kill A Mockingbird"). Only ten of them impressed me enough that I am reliably drawn in when they come on TV.

Top marks:
2001: A Space Odyssey
A Clockwork Orange
Apocalypse Now
Blade Runner
Casablanca
Citizen Kane
The Godfather
Pulp Fiction
Saving Private Ryan
The Shawshank Redemption

Okay:
Chinatown
Dr. Strangelove
Easy Rider
Forrest Gump
The Godfather Part II
The Graduate
Jaws
King Kong
Mr. Smith Goes to Washington
Platoon
Psycho
Raiders of the Lost Ark
Rear Window
Rocky
Schindler's List
The Silence of the Lambs
The Sixth Sense
Spartacus
Star Wars
Titanic
To Kill A Mockingbird

Enh:
Annie Hall
E.T. The Extra-Terrestrial
The Maltese Falcon
Tootsie
Vertigo
The Wizard of Oz