Aside from The Bourne Identity, Robert Ludlum sucks.
Tom Clancy is my 2nd favorite author, but some of his novels, especially lately, are plodding and uninspired. Rainbow Six is amazing, though. A lot of people probably think I have Rainbow Six as my avatar because I'm a gamer. I don't own a single game or any platform. I love the novel enough that I've worn a "Rainbow" patch with my loadout for years.
I can't recommend Stephen Hunter highly enough. Start with Point of Impact and read in order. I read a fair bit, and I can guarantee you he will blow your mind with his Bob Lee Swagger and Earl Swagger novels. No, not every one is grand slam, but unlike Clancy, even Hunters worst novels move fast and keep you entertained. He also goes out of his way to get all the little things about rifles and shooting culture right on.