Readers picked The Christian Delusion: Why Faith Fails, edited by John W. Loftus, as the Best Atheist Book of 2010. This is a great choice for Best Atheist Book because Loftus brings together many different atheists and skeptics — experts in fields like psychology, medicine, and anthropology — to critique the reasonableness of Christianity from multiple directions. Loftus' book has ten authors and fifteen chapters of skeptical critiques of orthodox Christian doctrines and general religious and theistic beliefs.
Some religious theists complain that atheists have no new arguments to offer but that's not entirely true. There are both old and new arguments in John Loftus' book and that may be why so many people voted for it for Best Atheist Book — it has something to offer a lot of different readers no matter what their level of experience and background. The variety of perspectives is helpful because readers are treated to some great scholarship in several different fields instead of just one.
These days there are far more books on atheism and by atheists than there was a decade or so ago and the quality of these books keeps going up as well. All of the candidates for Best Atheist Book of 2010 are well worth reading and I hope this poll encourages more people to go out and look at those book for themselves. You never know what you'll learn.