Hi,
A few weeks ago Kat (janeothejungle) recommended Harry W. Greene's Snakes: The Evolution of Mystery in Nature to me. I started reading it, and it's the best herp book I've read to date.
Unlike some of Chris Mattison's works, this book actually has more scientific perspective to the world of snakes.
I haven't finished the whole book yet, but have gotten quite far already. I definitely recommend it to anyone interested in snakes and who wants to learn (a LOT) more about them.
Thanks,