Website io9 has a list of best 15 speculative fiction books for 2010. Curiously it includes The Windup Girl (2009) published in the prior year. Apparently, it's just too good to ignore no matter what year it came out. It's a sturdy enough list, and sent me to look up a couple titles I hadn't heard of.
More varied and more exhaustive, is the Strange Horizons compilation of 26 reviewers presenting their best of 2010. There are a lot of interesting reading suggestions here.
If year's best lists aren't enough, Tor.com is inviting readers to vote for the best science fiction and fantasy novels of the past decade (their decade has 11 years, go figure). Over at Strange Horizons, Niall Harrison recapitulates the Tor.com best of the decade results and adds his own picks. His list overlaps with only one title in the Tor.com results: Jonathan Strange & Mr. Norrell (2004) by Susanna Clarke. I've only read six on the Harrison list and I already like it better than the Tor.com results.
Edited to add: Gwenda Bond offers a mostly young-adult oriented Top Ten for 2010, more evidence of the strength of this growing segment of the genre.