Just finished Martin's Game of Thrones books 2, 3 and 4. Great stuff, although I was a little disappointed with book 4.
Just started Clarke's Rendezvous with Rama. Great concept. So-so execution thus far.
I also picked up David Brin's Uplift War used but I may wait to get first book before reading this one.
Since I've started playing Star Trek online again with the Romulan expansion I may start reading the Typhon Pact books as I have a Trek book hankering.