I just beat my personal best. I read Max Brooks's "The Zombie Survival Guide" in less than 36 hours. Including the time I spent sleeping and working. I have never picked up a book like this.
As the name implies, it's a book about surviving Zombie infestation and attack. Max plays it straight throughout the entire book. He does such a good job of treating the subject matter seriously that I have to admit that after reading the book, I googled for some of the fictional people and places he refers to in supposed zombie attacks of yester year.
Once I read the first chapter, I couldn't put it down. Just for a moment, imagine that you live in a world where Night of the Living dead has happened. Also imagine that the zombie outbreak has been contained and dealt with. Lastly imagine that someone took the time to compile all known evidence about the zombies and condense it into a survival manual. This book puts you in that world. After reading this book, I have found myself looking at windows and thinking "those will never hold off any more than 4 or 5 zombies".