Adam Shostack's Threat Modeling
The book is an honorable mention finalist for “The Best Books” of the past 12 months. This is the first time a security book has been on the list since my Applied Cryptography (first edition) won in 1994 and my Secrets and Lies won in 2001.
Anyway, Shostack’s book is really good, and I strongly recommend it. He blogs about the topic here.