The novel Dune is so much better than the movie adaptation. I went to see the movie Dune when it first came out, with a friend who was recovering from an illness. Unfortunately, her illness was not completely gone after all and we had to leave the theater early, so I missed the last 30 minutes or so of the movie. And for that I ended up peculiarly grateful.
In the dark ages before blockbuster movie rentals, there was two alternatives to finding out the ending of the story. Pay to see the movie again, or get the book. The book was easier to get so I read it. And ended up very glad that I did, as the scope of the vision of the sand planet Arrakis and its people was so much grander therein than had been shown in the movie. Frank Herbert's fictional social patterns, history, religion and philosophy were so intricately designed and well constructed as to make the Star Wars world view seem to be built of tinkertoys by comparison.
I was surprised to learn recently that Dune would be re-adapted again in 2010. Hopefully, this new adaptation will be truer to the vision than was the 1984 adaptation. Sadly, I think it is unlikely that they will find as good an casting as Sting as the Harkonnen Feyd-Rautha.