The most recent nonfiction book I read was Cartwheels in a Sari: A Memoir of Growing up Cult by Jayanti Tamm. It was fascinating to get an insider's view of a faith so different from my own, yet the struggles we both have be so similar. Jayanti tells her story with humor and compassion - both for herself and for the guru who turned out to be a sham.
The nonfiction book that I still think of often, however, I have already reviewed. So, out of sheer laziness, I will refer you to this post. Little Brother and I were just discussing Nick Popaditch the other day. My "face of the Marines" brother still hasn't read it. You should.