Warrior Soul, by Chuck Pfarrer, is a fascinating look inside the SEAL community during the 1980's. Not as laden with bombastic machismo as the Marcinko stuff so popular with the Mall Ninja crowd, it's well-written, as honest and introspective as only a psych major could write it, and makes a good pair with One Perfect Op for reading on a long weekend.
To enjoy this next one, you have to be a geek. More specifically, a history geek. Even more specifically, you have to be a history geek who's curious about any possible organized violent goings-on in neolithic and Bronze Age Europe, back before everybody caught a bad case of literacy from the Minoans. Also, you need to be able to read about warfare as described by the pointy-headed faculty from the soft sciences departments. If you fit these qualifications, buy Ancient Warfare, a collection of writings from various archaeologists, paleontologists, and anthropologists, collected and edited by John Carman. Probably all five of us who are interested have already read it, but one never knows...
Lastly, I finally got around to reading Callahan's Legacy. As usual, a very happy book. As usual, very hard to describe to anyone who hasn't read any of the series by Spider Robinson. (Basically, a bunch of drunks tell bad jokes, love each other, and save the world, then pay their bar tabs and go home.) A Callahan's book is like going to the zoo: Either you're happy to see the giraffes again, or you're not. Me? I love giraffes.