I just finished reading The God Delusion by Richard Dawkins, and without question I would add this book to the list of books I feel all human beings should read ASAP. Richard puts all of his ideas into such an easy to understand context all while being extremely elegant. This book will make you laugh and then cry.
Richard was preaching to the choir while I was reading his book, but despite already being an atheist and having read a decent amount of material on the topic, I was able to learn a whole lot of new things. Hopefully, this book will find its way into the hands of people on the fringe. It might be asking too much for it to find its way into the hands of fundamentalists though. Personally, I try to read books that I know contradict explicitly with my current beliefs.