Definitely worth it. I'm about 3/4ths of the way through the first book, and it's some good stuff. Even if sci-fi isn't your thing, the characters are pretty rad. Especially Gurney and Piter.
Yes, reading the complete works of Dostoevsky, or making love, or travelling the world just pales in comparison. No wait...
Dune is a modern classic. Whether you end up loving or despising it, you should read it. It has themes woven through it that are even more relevant than when it was written. I don't like all of Frank Herbert's writing. Some of his other works struck me as preachy and somewhat simplistic. However, Dune is a rich tapestry of politics, religion, destiny, ecology, and culture.
