I tend to go for the classics - I especially love the old musicals and comedies.
Old musicals (An American in Paris, Singin' In The Rain, West Side Story)
Bringing Up Baby
Any Abbott and Costello movie
Anything with Clint Eastwood, old and new
The Gods Must Be Crazy (this movie ALWAYS makes me laugh hysterically)
The Lord of the Rings Trilogy
The first 3 Star Wars movies
Amadeus
The Indiana Jones movies
A Christmas Story
Mel Brooks movies
Alfred Hitchcock flicks (Rear Window, Vertigo, Psycho)
Classis Disney films