If y'all are going to go with The Lord of The Rings, then I am throwing in The Harry Potter books. The books were o.k. (not great, or even particularly well written, just good), but the movies were much, much better.
For example, the books spend a book and a half on the Elf Liberation Front, which goes nowhere and is suddenly dropped in the fifth book (I think). Also, the end fight in the movie is incredible and epic. In the book they square off, Harry says "You can't defeat me because your want belongs to me". Voldemort casts a death spell, but, since the wand belongs to Harry, it backfires and Voldemort dies. That is it. It is over in ten seconds, Harry does nothing at all and it is as anti-climatic as hell. I read through all seven books for that ending? No thanks.
For example, the books spend a book and a half on the Elf Liberation Front, which goes nowhere and is suddenly dropped in the fifth book (I think). Also, the end fight in the movie is incredible and epic. In the book they square off, Harry says "You can't defeat me because your want belongs to me". Voldemort casts a death spell, but, since the wand belongs to Harry, it backfires and Voldemort dies. That is it. It is over in ten seconds, Harry does nothing at all and it is as anti-climatic as hell. I read through all seven books for that ending? No thanks.