Fingerprints of the Gods by Graham Hancock
d_ka_b_2_1/002-6028218-1237654">http://www.amazon.com/exec/obidos/ASIN/0517887290/qid=1097864520/sr=2-1/ref

The author does a wonderful job of linking ancient civilizations through known time. It is a well written book and presented well, If you want something to read that will make you stop and contimplate everything that ever was then this book will do it. Warning upon reading this you will probably also be convinced the world will end in 2013 when the Myan calendar finishes its countdown of this cycle.
And of course my favorite book ever. If every human read this book people might actually use their brains...
Gödel, Escher, Bach: An Eternal Golden Braid by Douglas R. Hofstadter
d_ka_b_2_1/002-6028218-1237654">http://www.amazon.com/exec/obidos/ASIN/0465026567/qid=1097864965/sr=2-1/ref

This book can push the limits of thinking, it is just best to take it all in and sort it out later. I've read this book front to back a large number of times, each time I feel newly awakened and conscious in some new way. It is book about logic, logically evaluating human thought and creativity. The name of the book is Godel, Escher, Bach but the book is not actually about them although it does use their works and talents as part of discussion. Read this book, please, your mind will thank you (or hate you for having to actually work).