The Everything Body Language Book by Shelly Hagen (2008, Paperback)

I liked this book about body language more than most.
First off, it doesn't really preach a point of view as to why body language is what it is.
The author just lays it out. This means this, that means that.
Of course, she correctly points out that no individual behavior means only one thing, a point some books don't emphasize enough.
She also covers involuntary body language, such as flushing, trembling, etc. She presents a good section on facial expressions, bordering on Paul Ekman's FACS.
As do most body language authors, Shelly assumes you are reading this book for a reason, and so illustrates behaviors with situations. She does this to good effect.
Throughout the book, there are "idiots guide" style notes that do add something to the content.
All in all, well written, espeically for those who want a full spectrum of behaviors but don't want to get bogged down in a clinical analysis of human behavior. If I was to only have one body language book in my library, this one would compete for top honors.