People that say movies aren't an art form needs to wake up. Also, while it's true that movies based on a book fall flat more often than not, movies in themselves can portray emotion and circumstance that engages your mind in a whole other way. So, I'll start with a few of my favourites!
The Royal Tennenbaums
The Life Aquatic
Pulp Fiction
2001: A Space Odyssey
Papillon
Iron Man
Sideways
Forrest Gump
Robocop
Contact
Close Encounters of The Third Kind
The Incredibles
Four Rooms
Kill Bill 1&2
The Pink Panther Movies (not the Steve Martin drivel)
And many, many more....