I have had a lot of professional exposure to doctors over the past 10 years. There are a lot of good and some really bad physicians out there (mainly those who think they know everything)
Where do you live? Do you have any health concerns that need to be addressed? Your best bet is to find someone close to your house - nothing worse than a long drive when you are sick or in a hurry. If you don't like them, find someone else. There are a lot of Family Practitioners/Internists, and you should easily be able to find someone with the bedside manner you are looking for.
Personally, I'd never been a fan of my own FP - thought he was a little weak on some information - until he got the ball rolling on a swollen lymph node and got me diagnosed with cancer a year ago. Now, I'm much more confident in him!
It can be expensive to change practices - think about that, too.
Just because an office is busy, doesn't mean the physicians are any better. In some cases, insurance may dictate who you see, and that may have just filled-up the appointment book vs. a good doctor.
Angie's list now rates doctors as well as some other sites. Ask your pediatrician or OB/GYB for referrals. Chances are, they see a lot of referrals from someone or may have gone to med school or done residency with someone really good.