I think it's much more faithful to the original material than I, Robot was, but still not enough. They've lightened the mood of the story much too much for my taste, but still, I did manage to enjoy the movie, although I've never felt the inclination to watch it again.
I can think of a couple. One of the most famous (and to me, most surprising when I found out) is the original Dune movie by David Lynch. Frank Herbert worked directly with David Lynch on the movie, and was overall satisfied with the results, even though lots of filmed material was cut from the final movie. He gives an account of his work on the movie in the introduction to his book Eye.

Oh my, great movie based on great novel. I got pretty lucky yesterday by picking up the game pretty cheap. Off to watch the movie again!