Agreed, I think I've read all his books. I quite like his writing style, fairly casual and humorous, enjoyable to read.
The Hunter Killers is probably one of my favorites, Its about the first Wild Weasels in Vietnam. Lords of the Sky is quite god as well, encompassing almost every era of combat flight "From the Red Baron to the F-16" If you interested in something different, his novel The Mercenary is an interesting fictional story, Although be warned theres actually very little flying in that book.