|Accelerando, by Charles Stross. Ace, 2006.
This novel explores the Singularity: What happens when AI, uploading, and other variations of humanity (or non-humanity) start to happen. I was worried that a novel on this subject would basically be, "Computers take over, and who knows what they're thinking?" Instead, we follow the protagonist's family through generations, and get a plausible and enjoyable flavor of what the Singularity could mean.