Dune is, IMO, the best, SF books of all time. I have now read this four or five times and I can see where so many other authors have borrowed from the work of Frank Herbert. The entire series is good, but the first one was a masterpiece.
Hebert is one of the few authors who can do it all, and do it remarkably well. He is a storyteller supreme, keeping you on the edge of your seat, poised to turn pages the instant the last word is read. He is an intricate plotter, creating mastermind plots that reel you in, twist you around and keep you wondering what is coming next. His character development is incomparable. Every one of his "cast of thousands" is deep and consistent and interesting. Whether you hate them or love them, there is no denying that they are well developed. The fact that you will both hate and love them is proof. He digs deeply into science to construct the planet and its ecosystem, and he delves even deeper into religion for some of the races of people and their beliefs. I have only read a few books as purely satisfying as Dune, and it's one I will keep coming back to.