Lemme point you guys to some slightly less mainstream choices. If I may.
The Etched City - K.J. Bishop. If you like Mieville, this will destroy your mind and rebuild it into a beautiful, eternal structure of joy. Maybe. Or you may just enjoy it a lot.
Counting Heads - David Marusek. Science fiction is an ongoing conversation. Asimov and Pohl started the modern genre, The New Wave responded to that, Gibson and Stephenson and Sterling responded to that. Marusek is the next step. Fucking genius, in the way Stross can sometimes be.
Vellum - Hal Duncan. It's hard to describe this. Good. Very, very good. Occassionally impenetrable, but Hal is one of the smartest guys I know, and this novel is testament to that.
Not books specifically, but a great source of vibrant science fiction and fantasy is the current small press and zine scene. Seriously, the best fiction is coming out of people's basements, not the big house presses. Check out Nightshade Books, MonkeyBrain, Electric Velocipede, Flytrap, Say..., Strange Horizons, Lady Churchill's Rosebud Wristlet and Pyr Press. Fookin' great.