Though I'm an atheist to the max, I find this kind of thing to be very disagreeable...

Anyway, I read Dawkins this summer and found my favorite book to be The Extended Phenotype, mainly because the ideas in it connect with (directly or indirectly) the current and exciting ideas of Luis P. Villarreal's virology and Kevin Laland's positions on niche construction. The other top books are The Selfish Gene and The Ancestors Tale.