Never read God Delusion... it is on the list though. Personally I am against any "scientific" or "logical" arguments that prove or disprove the existence of god(s).
A book that I did enjoy reading (as it doesn't go to prove or disprove anything, only explain why man created would have god):
The Origin of Consciousness in the Breakdown of the Bicameral Mind by Julian Jaynes
I actually bought this one. Jaynes starts off with a definition of what it means to be conscious and what roles consciousness actually plays. He then explains how the modern mind evolved from a non-conscious mind where each hemisphere of the brain was an independent processing unit that spoke to one another, hence why man heard the voice of God.