Like someone else said, the Culture books by Iain M. Banks are good, try
Consider Phlebas - a shapeshifting human is hired by one side of a huge interstellar war to capture an errant, sentient supercomputer made by the other side that has fled to a remote planet.
Kiln People by David Brin was quite good - in the future, people can make cheap, temporary clones of themselves to go to work and do other menial tasks for them. The main character stumbles on a conspiracy involving the inventor of the clone technology.
Rendezvous with Rama by Arthur C. Clarke is a classic. A gigantic, cylindrical alien craft, dubbed Rama, enters the solar system, and a mission is launched to investigate. The sequel was pretty good, too.
Altered Carbon was quite excellent. Here's a review [http://www.escapistmagazine.com/forums/read/326.81194#1076224] I wrote for it
EDIT: crap, sorry - I didn't see that you've already read
Consider Phlebas