U.S. Submarines Since 1945, Revised Edition
 

This recently came out about four months ago. Let me say it was a pleasant surprise to hear of this edition being revised and in print again. The information within is phenomenal and, for me in particular, provides a great source of OSINT. The price is much more affordable than its predecessor, starting at $55 for new condition compared to the almost $200 for the previous version. I consider this a must have for any researcher or enthusiast.