Saboteurs by Michael Dobbs - a very interesting account on the Nazi effort to land saboteurs in the US to cause havoc.
Given Up for Dead by Bill Sloan - a detailed account of the battle of Wake Island and what happened to the defenders after the battle ended. Notable as the only time in history the Marines have surrendered.
Last Stand of the Tin Can Sailor - Probably one of the best books written about the US Navy during WWII, definitely a very good read.