This is really great. New York State created the NY Doctor Profile site so you can research a doctor's background (educational, certification, professional activities) and find out if there are legal actions against them. It's really hard to find a primary care physician that takes your health care insurance (Aetna in my case) without word of mouth. This helps a lot to at least weed out obviously bad choices.

There is also New York Magazine's Best Doctors list, but I doubt that most of them take insurace.