I cannot think of a movie that was better than the book but then again, I never read Lonesome Dove.

One of my favorite authors is Carl Hiassen. His books are absolutely hilarious. Only one was turned into a movie that I know of and that was Striptease. It bombed. When interviewed years later and asked why it was unsuccessful he said that experience taught him the importance of a narrator in his books. The narrator in a book has the ability to describe a scene or an action in a comical fashion. That narration can't be captured on camera.