Robert L. Scott's God is My Co-Pilot. Good, just keep in mind it was written during the war with propaganda purposes.
Peter Townsends Duel of Eagles. One of my all time favorites, about the Battle of Britain. Gives background info as well as Townsend's narrative, which is pretty engrossing to say the least.
For present day, of course Keith Rosenkranz's Vipers in the Storm. The diary of a Gulf War F-16 pilot.
Robert Wilcox's Black Aces High tells the story of the VF-41 Black Aces (an F-14 squadron) during Operation Allied Force over Kosovo. Also good stuff.
Douglas Wallers Air Warriors. I liked it a lot, chronicles USN pilot training.
As for fiction, might be my favorite book EVER. A must read if you haven't is James Salter's The Hunters. It follows an F-86 pilot's tour in Korea. It's by a good novelist who write fiction primarily, and is beautifully written. Salter himself was an F-86 pilot in Korea, scoring one MiG-15 kill, and much of the main character is certainly autobiographical. So if you haven't read this, do so. Now. Go. It's a short, easy read.
PD