Executive Orders was the last one that I liked a lot. I guess Rainbow Six was pretty good but kind of.. video gamey, maybe? You can totally divide it up into levels and a final boss encounter. Bear and the Dragon and Red Rabbit were kind of meh, and Teeth of the Tiger I didn't like at all. Didn't read any after that but I guess they were "co-authored"/ghost written then anyway.
Favorites were Red Storm Rising, Sum of All Fears, and Without Remorse. I seem to remember liking Red October a lot too but at this point all I can remember is the movie.