Larry Vickers, Paul Howe, or Ken Hackathorn...
Clint Smith and Pat Rogers.
Jeff Gonzalez is supposed to be pretty good too, but I have no experience there.
Some people get all pissy about a class being too "basic." The basics are the foundation and a majority of the people need work on the basics. Lots of people want to do the sims (houses, cqb kind of shit) because its fun (and it is) but they fucking suck at the basics and get bad hits, fuck up their manual of arms, etc. I've taken a bunch of the advanced carbine (and pistol) classes... I still sign up for basic classes every year, it makes you better, and hell, it can't hurt... Hell, I take some of the same classes repeatedly.
FWIW: I have heard good things about Yeager, never met him, but I have heard good things about the guy.
ETA: Awerbuck is awsome too, I forgot to mention him.
But, the best by far is Ken Hackathorn, he is the tactical dali-lama.