The Seventh Seal (1956)
Written and Directed by Ingmar Bergman
Based on the Play by Ingmar Bergman
In Swedish with subtitles

A knight named Antonius Block returns to his native Sweden from the Crusades, only to find the country ravaged by the Black Death. He wanders, trying to find meaning or simply make sense out of the chaos he's stepped into, persued by Death personified. The movie focuses on a chess-match between Antonius and Death himself. It's essentially a tale of death's inevitablity, the absence of God, doubt, and uncertainty.

The Seventh Seal is a rich example of cinema art at its best and the philosophical de profundis it imparts is simply mind-blowing.
It's like Existentialist porn.

For further info, I'd recommend Roger Ebert's excellent review at: