In 2011, the best book I read was Steve Jobs, that remarkable biography. So far this year, my favorite is Spillover by David Quammen, the science-medical-history-travel nonfiction book that reads like an adventure novel. Quammen even commented on this, noting that "nonfiction could be wondrous and imaginative, shapely and literary — it didn’t just have to be explanatory.” The book has an ominous theme because it is about zoonotic diseases, those that pass back and forth between animals and humans. This is not only the best book I've read this year, but also one of the best I've ever read.