I was right. I was thinking about this question too much to sleep. So here are some more:
Deliverance. I didn’t like the movie but I hated the book.
I haven’t seen The Last of the Mohicans, but it has to be better than the book. I was halfway through before I found it interesting. A lot of that crap had to have been taken out to make it fit into film format.
Requiem for a Dream. Things of that nature affect me more in visual media. The book bored me. I’m not even sure if I ever finished it.
A Series of Unfortunate Events. Stuffing three books into one movie made it good. Those books drive me nuts. They’re painfully episodic.
Persepolis. The book is amazing but the movie is perfect.
Rear Window. There’s just so much more to the film. Hitchcock pwns all. I may have also liked Psycho better as a film than as a book. I think I need to reread that one, though.
Brokeback Mountain. Annie Proulx’s writing style doesn’t work for me. Likewise, I prefer the Lord of the Rings movies to the books. Tolkien told fantastic stories but he told them in a way that makes me fall asleep. Alas.
Also, I like Clueless better than I like Emma. Does that count? :D