(In no specific rank in each category)
Horror:
Night of the Living Dead
Exorcist
Poltergeist 1/2(that fucking preacher)
The Mist
The Shining
Comedy:
Spaceballs
Big Lebowski
Caddyshack
Anchorman
Old School
War:
Braveheart
Saving Private Ryan
Shindlers List
Gettysburg
Full Metal Jacket
Action:
Bloodsport (always will be a favorite)
Big Trouble in Little China
Roadhouse
Tombstone
Goldeneye
Gangster:
Goodfellas
Godfather 1
Casino
The Departed
Godfather 2
Adventure:
Princess Bride
Lord of the Rings- The Two Towers
Inception
Indiana Jones(any that he kills nazis)
Star Wars- Empire Strikes Back
There are entirely too many good movies to even make top 5's in a lot of categories
hard picks!