After jwfacts.com and Crisis of Conscience:
Shepard the Flock of God (2010 Edition)
The God Delusion, by Richard Dawkins
Captives of a Concept (Anatomy of an Illusion), by Don Cameron
Leaving the Fold, by Marlene Winell
Books that later helped me to understand cult mind control:
Combatting Cult Mind Control: The #1 Best-Selling Guide to Protection Rescue and Recovery from Destructive Cults (2010 Edition), by Steven Hassan
Releasing the Bonds, Empowering People to Think for Themselves, by Steven Hassan
Freedom of Mind, Helping Loved Ones Leave Controlling People, Cults and Beliefs, by Steven Hassan
Even later in my personal recovery:
Take Back Your Life, Recovering from Cults and Abusive Relationships, by Janja Lalich and Madeleine Tobias