The Body

A tour-de-force tour of the human body - organs, systems, glands, everything you could imagine. Written for the layperson but chock-full of amazing anatomy explanations as well as factoids that you will want to remember for future conversation but of course will never be able to keep track of (the liver is part of 500 different metabolic processes and contains a quarter of all your blood). Fascinating digressions about particular diseases, scientists, discoveries and yet more facts. (And if you're an audio-book lover, Bryson's own reading of the book on Libro.fm is fabulous.)
David