woah this it tough...

Drama: City of God or Shawshank Redemption

Comedy: Baseketball or Airplane or Blazing Saddles or Lost in Translation or Duck Soup (Marx Bros.)

Action: Bourne Identity or Boondock Saints or Days of Thunder (FANTASTIC with Surround Sound)

Musical: Dancer in the Dark or Southpark the Movie Bigger, Longer, Uncut

Thriller: Usual Suspects or Mystic River

Horror: Fallen (w/ Denzel Washington) or Stir of Echos

Family: Emperors New Groove or Harry Potter Movies (they are very well done IMO) Shrek is good as well.

SciFi: Matrix or 12 Monkees

German Film: Run Lola Run

Pirate: Pirates of the Carribean

Western: Tombstone

Beautiful Film: American Beauty or The Red Violin or Big Fish or Life as a House (or is it Life is a house?)

EDIT: Added..
Mobster Movie: Any Godfather or Casino or the one where Pacino is a cop after DeNiro that's great stuff