It's really hard for me to pick favorites but here's a quick stab at it...
General: The Natural, The Princess Bride, Notting Hill
Classics: Mr. Roberts, It's a Wonderful Life, Hellfighters
Westerns: Quigley Down Under, Dances With Wolves, The Shootist, The Searchers, True Grit
Strange Stuff: The Adventures of Buckaroo Banzai—Across the 8th Dimension
SciFi/Fantasy: The Star Wars saga; Star Trek II, III, IV, First Contact; Labrynth; Silent Running
CG/Animated: The Incredibles, The Lion King, Shrek