I'm a surgeon, and it often amazes me how many of the the highly educated people in my town go to doctors that I (and many of my colleagues & nurses ) wouldn't let touch our families with a ten foot pole. Marketing should not be how you pick a physician. Even references from a family physician to a specialist are typically biased, if that doctor is employed by a hospital or large group, and will invariably recommend their partner, rather than an arguably "better" competitor.
Many of the best primary care doctors don't take new patients - they are full and have closed their practice. Many of the best surgeons/specialists are really booked up, and will take longer to get in to. Newer physicians who have not yet "proved themselves" and built a busy practice, as well as those that are truly not that good - will be easier to get into. Don't fall for it. Quick access does not equal good quality.
Online review sites are quite literally worthless.
The best way to find a physician is asking those that work with them, and have an idea of expertise and/or outcomes. Looking for a good orthopedic surgeon? Ask the physical therapists that rehab their patients. Looking for a good general surgeon? Ask an intra-operative nurse or surgical assistant (that is not tied to a specific surgeon.) A good neurosurgeon - ask physical therapy or a pain specialist. I realize not everyone personally knows these types of health care professionals, but I think most people at least "know someone that knows someone that is" and can get a recommendation.