Le Samourai, directed by Jean-Pierre Melville.
This 1960s French Noir masterpiece stars Alain Delon as Jeff Costello - contract hit man, loner, and without question the coolest looking guy you'll ever watch on screen. Considered by subsequent generations of film directors as a key influence on their own work (i.e. Scorsese, Taxi Driver), the film cross-pollinates gangster, samurai and French cinematic artistry to create its own hybrid of stunning minimalist noir.
Rotten Tomatoes LOVES this film. And here's a NYTimes review from a 97 International Film Festival.
Hi-Def, popcorn, and a free movie. What more could you ask for?