I've been watching House and Senate hearings on C-SPAN almost incessantly this past year and while I've probably not seen every hearing, I think I've seen enough to be confident that Barney Frank is, hands down, the best Chair in either House. He may also be the smartest (intellectually and politically) politician in Congress.
Although Frank can be darn difficult at times to understand, he knows his subject, he knows the parliamentary rules, he knows the people on his committee, both Republican and Democrat. There is a limit to his patience with Republican shenanigans, and he has both a sharp tongue and a sharp wit.
Although I don't always agree with him, it is clear to me that often, when he veers rightward, he does so because he knows just how far the Dems can go and still get something passed.
I'm also coming to appreciate Stupak, who chairs a sub-committee for both the way he manages the committee and for the clarity and relative succinctness both of his opening statements and questions.