This is a classic science fiction book with both movies and miniseries adaptations, so I assume the majority of the people are familiar with the plot which means I will be a little less careful about giving spoilers than usual.
In the distant future the humanity is ruled by an intergalactic feudal Empire - is absolute monarchy the best the humanity could come up with after all its history? Anyway, Duke Leto Atreides accepts control of a desert planet called Arrakis (aka Dune) which also happened to be the only source of some substance called spice which importance is slowly revealed in the course of the book. By the way the reasons for this duty and its acceptance are at best murky to begin with and they are never explained and become even more unclear down the road.
Dune used to be a stronghold and the major source of wealth of Duke's sworn enemy Baron Vladimir Harkonnen who actually somehow managed to arrange the whole thing to finally deal a mortal blow to the Duke.
And so the story begins. I just barely scratch the surface of it as it deals with a lot of intrigues, politics, religion issues, secret societies, survival on the planet which never saw a single drop of rain and where the wealth is counted in the amount of water owned. The most importantly, this is a story about the danger of creating a hero prophet
The book was originally published in 1965 and it does show its age, especially in the light of countless other books it inspired with the quality of the latter ranging from really pale imitations to great pieces of literature in their own way. I would not even call it a work of science fiction in the modern definition of the world. A relatively new term "sword and planet" would be a better genre description for it.
I already mentioned the inspirations and imitations of the book. The reason for them is a very detailed world which looks completely unlike ours, yet is so similar to it. More importantly, it feels alive with its own landscapes, culture, religion, people, their rivalries and friendships. The worldbuilding is top-notch easily holding its own against undisputed king of that in fantasy, Middle Earth.
The characters and their development are different story though. The only character who feels completely 3-dimensional with a good development is Paul Atreides, the Duke's son. I can somewhat agree that Jessica almost - but not completely - qualifies. The rest of the characters feel like cardboard cutouts, even the most important ones like Stilgar. As to the Baron Vladimir Harkonnen: he looks like an absolutely static caricature with practically all imaginable bad human indulgences thrown into to make him look completely repulsive.
The strengths of the book easily overweight the weakness I mentioned before; the latter can be easily overlooked. The book became a victim to its own hype: it does not deserve the title of the most important and the best science fiction work ever
which it is often credited with. Due to all the hype I am a little disappointed - enough to lower its rating by half a star.
This review is a copy/paste of my BookLikes one: http://gene.booklikes.com/post/897366/a-classic-science-fiction-book-while-aged-a-little-is-still-a-lot-of-fun