What book do you think should be made into a movie? And do you have any suggestions for the producers?
Or, What book do you think should NEVER be made into a movie?
I'll do both.
As for a book that should be made into a movie, I'll go with The Hobbit -- since the plans are currently in place, and I think it would make a really enjoyable film. Given the success of turning Lord of the Rings into films, I trust that The Hobbit could be done tastefully and authentically, as long as the producers/director don't try to make it too much like Lord of the Rings. The books are very different and should be treated differently on film.
As for a book that shouldn't, I recently heard that Hilary Swank's production company had bought the rights to French Women Don't Get Fat. It's a diet book -- so I have no idea how it would be made into a movie, but apparently some desperate soul is going to attempt it. Somehow I don't think it has book-to-movie potential, but perhaps a good screenwriter will prove me wrong. If I were to offer another Tolkien response, I'd have to say that The Silmarillion should never be made into a movie, but I seriously doubt anyone would attempt it. That would be like turning the book of Leviticus into a film.