I read as much nonfiction as fiction, but the vast majority of my favorite authors are novelists. There are two main reasons for that: I'm an aspiring novelist myself, so fiction writers are my natural role models, and most of my nonfiction choices are driven by my interest in the subject matter rather than the author.
But there are a few exceptions, and one of them is Bill Bryson. He's funny and insightful, he's in love with language and history, and he's got a knack for making everyday life in both his native U.S. and the UK, where he lived for many years, seem fascinating.
Where to start with Bryson:
1. A Short History of Nearly Everything: The title overstates the case a bit--it's a history of science, of how and when we figured out what we know about the world, with a focus on the quirky personalities involved. I mean to use this one in my writing one of these days--write a fun novel about an almost-mad scientist.
2. The Mother Tongue: A history of the English language, with plenty of humor.
3. I'm a Stranger Here Myself: Bryson endures culture shock and offers an outsider-insider perspective on returning to America after two decades in England.