If you liked "The Da Vinci Code" you'll enjoy "Angels & Demons: which was published earlier but didn't make quite as big a splash. I listened to this book on CD.
I couldn't put this down, and like how the author lets you feel smart by telegraphing a few of the many plot twists. I've heard it's very much like the Da Vinci Code, which I'm reading now. I've also heard the Da Vinci Code is better, but maybe that's because most people read it before Angels and Demons.
A catastrophic bomb has been stolen and hidden in the Vatican! It's up to Robert Langdon to find it before it explodes by doing what he does best, solving more riddles. This book comes before the DaVinci Code. So you will like this if you like the DaVinci Code. I like Angels more than DaVinci because it has more action and finding a bomb that will destroy the Vatican and parts of Italy seems more pertinent than protecting the lineage of Christ.