What's a great book that was poorly executed in a movie?

Ender's Game

Excellent book--movie was mediocre at best.

The Girl With The Dragon Tattoo et al. They tried to pack too much into three ordinary-length movies. It didn't work.

Dear HappyTwo,

I also used this as a GOOD example of a book that was rendered well in the movie version...

But I was entranced by LILITH, starring Warren Beatty, Jean Seberg, and Peter Fonda, based on the book by J.R. Salamanca. The acting was exquisite, but the book was so fine and subtle that I could not really appreciate the movie until reading the book.

No fault of Director Robert Rossen, just no way the story could have been rendered any better I believe; an amazing and sympathetic study of madness.

The Hunt for Red October ! Movie was OK but not any where near as good as the book.

I loved the book Flowers in the Attic when I was a kid ... The movie was shizit. That was a hundred years ago though so I'm over it.