What about classics like the Godfather or Gone with the Wind, or films like Apocalypse Now, The Shining, and No Country for Old Men? What about films made from 19th C novels by Jane Austen or Henry James? I think those are all films that are either as good as or better than the book or that I am more likely to enjoy.
What about Shakespeare? (Not novels, but you're more likely to read them than see them on stage in most cases.)
I am looking forward to seeing The Road made into a film, that will be interesting. I think Cormac Mc Carthy's books lend themselves to film adaptations because the conflict is largely externalised but I love his books simply for the vocabulary if nothing else.
I agree that reading the book and seeing the movie is the best as long as both are decent.