Hmm, I have seen a few movies, but have yet to read a book.

Children of Men - even though the book and movie are vastly different I like them both.

Surprised no one has mentioned Jaws yet, but, yeah, JAWS the movie is far better than the novel, and was well rid of the gratuitous extramarital schtupping and pointless mafia subplot.

Misery comes to mind.

I was thinking Misery, but I liked the book a tad bit better. In the book...

But I do love both the book and the film.
:)

Not a movie, but I understand that Wicked carried over well (other than completely changing the end).

The Firm interpreted the first 2/3 of the book pretty well, but choked on the end.

Mommie Dearest

Sybil

shudder

Yes, I may have mother issues.

Tom Sawyer, Huck Finn, and Alice in Wonderland are three books that have never been adapted to film in a satisfying way. I'll also go out on a limb, and disagree with CP on Willy Wonka. I've watched the movie several times, and I find interesting things in it, but my love for the book keeps me from fully enjoying Gene Wilder's truly bizarre and off-putting performance. Why they continued this movie conceit of Wonka being a freak into the Depp version, I don't know. Eccentric in the book? Yes. Complete freak? No.

Hunt for Red October

I liked the changed endings much better in both of these than in the books.

Practical Magic - the characters in the book were not likable at all. Love the movie.