I love Stephen Hunter's series of books featuring Earl Swagger (set in the 1940s and 50s) and then his son Bob Lee, which spanned from the 1960s to the present day. However, the last two with Bob Lee which I read, the 47th Samurai and I Sniper, just didn't meet the (admittedly very high) standard of the earlier ones.
Interesting to know as I've just started reading that series (the Bob Lee one).
Incidentally, I've just started reading the latest one, Dead Zero. Am hoping it will be a return to form. Hunter maintains virtually no internet presence (there are only fansites, no official ones) and his books get little coverage in review columns over here, so it's always a pleasant surprise for me to walk into a bookstore (especially a second-hand one!) and see one of his books on the shelves.