The Righteous Mind: Why Good People are Divided by Politics and Religion, by Jonathan Haidt - Excellently written (please, please, everyone follow the practice of summarizing each chapter in an organized outline form...), endlessly fascinating. More to say on particular points later.
Snow Crash, by Neal Stephenson - I can't count how many people have told me I should read this, upon hearing I don't like sci-fi. They were very very wrong. Here's a good rule of thumb: if the author spends more time building up some arbitrary alternate universe than developing compelling characters, it is sci-fi, and I won't like it. Y.T. is great but can't carry the book on her own, and saying 'It's not sci-fi, it's cyberpunk fiction' is like saying 'It's not green, it's emerald.' And if I'm going to slog through endless tedious historical detail, I at least want it to be true. Also, the writing style is offensively aesthetically irritating. (Yet, Neal Stephenson can definitely be fantastic: read this.)
Song of the Dodo, by David Quammen - Very interesting book about island biogeography and extinction. But it could have easily been half as long, and his manner of turning scientific research into personal epics loses a lot of credibility after the age of world-exploring death-defying Darwin-esque research. I'd rather just have the unadorned facts... science is beautiful and compelling on its own. (Or, his shorter essays are amazing and a much better setting for his skills.)