This book was required reading for one of my classes last year, but it was amazing! America In Crimson Red: The Baptist History Of America gives little-known facts about our nation's history. After this read, you will never view Baptists quite the same way again!
Coming from a varied church background, I never really knew what it meant to be Baptist until I studied it at college. Now I'm a die-hard! =) Another great pick is Why Baptist? which deals with Baptist distinctives. Whether you're Baptist or not, these two books are a great addition to your personal library.