Dune

Well, clearly I am extremely late in this post but as they say better late than never. OK, I'm going to be brief in this one. Dune is of course one of the standards in the Sci-Fi genre and thus there is no way I would be able to really do it justice so I'm just going to bring up a few of the more interesting things I found in it.
First, the fact that Frank Herbert was able to create this entire space of existence and not, as far as I could tell, make any continuity mistakes is absolutely amazing. This is of course in contrast to the best known of this type the certain SRAW RATS that shall remain nameless. With all of the different groups from the Fremen to the Atreides, Harkonnen, the Emporer, the Sardaukers, the Guild it is astonishing the degree to which he was able to write in a back story without actually stopping to have to spell out every groups history.
Next is the freaky religious aspects of the book. So we have the Bene Gesserit making up all of these religious stories as a mass cover-up for their "weirding ways" and yet the prophecies come true on Arrakis.
Finally I have to note the combination of an old western feel within the Sci-fi. You have the Fremen who use knives against the others with Lasguns, 'thopters, shields and all the other gadgets they have and yet the knives win in the end. That's quite simply awesome.
I know this is late and by no means comprehensive but then again the book really speaks for itself.