"Fly The Wing" by Jim Webb. If you are an Air Transport Pilot, or are planning to be one, this is the flying book for you. Technique and theory are covered in detail. It is a bit dated, and is now out-of-print, but it is still available through on-line book stores.
"Chickenhawk" by Robert Mason is one man's account of flying a UH-1 Huey during the Vietnam War. Absolutely horrific.