Most philosophical movie of each decade
30s - The Hunchback of Notre Dame
40s - The Fountainhead
50s - Robinson Crusoe
60s - Easy Rider / Planet of the Apes (tie)
70s - Circle of Iron
80s - Crimes and Misdemeanors
90s - Pleasantville / Life is Beautiful (tie)
00s - Almost Famous / The Dark Knight / A History of Violence
10s - ?
Honorable mentions:
Waking Life
Death of a Salesman
The Truman Show
Being John Malkovich
Blade Runner
The Jerk
Groundhog Day
Gattaca
Simon Birch
What Dreams May Come
Thelma and Louise