he's a decent actor with a somewhat narrow range. his greatest asset is that he has mega charisma on screen and he is GREAT at picking movie roles.
my faves--the guy has been in a ton of things I really love:
Interview With a Vampire
Rain Man (he's underrated in this one)
War of the Worlds (if you can remove dakota fanning)
A Few Good Men
The Color of Money
bad movies: Far and Away--hate it, hate it, hate it
Days of Thunder
The Last Samurai
and a lot of his other stuff aren't home runs, but they're ambituous and creative, which makes them worth the price of admission: Minority Report, Vanilla Sky, Eyes Wide Shut, etc.