Definitely a tough choice but heres my 2 cents.
You have some pretty amazing opportunities on the table. The ability to get a near full-ride at Wake and receive in-state tuition at Miami are not too common and are huge accomplishments, congratulations on that.
I think Wake Forest is a great school and you would be receiving a private school education for a vastly reduced price. You would be coming out of medical school into your residency of choice and would be way below the national average for debt (which in this economy is starting to become a factor for many prospective doctors). The city of Winston Salem is developing very quickly, especially its downtown business sectors, and is becoming a very cool place for young professionals to live.
Miami - This is also an amazing opportunity. As a NC resident, you have the ability to see a different part of the country for the price of an in-state school. Miami is an OUTSTANDING place to study medicine, and the diversity and excitement of a very cultural, urban community would make your medical education more unique. I personally love to travel and would jump at this opportunity I think; I have heard nothing but great things about Miami and its a way to 'Get out there' in the world for 4 years while you study.
UNC- It's a great school as well, there's no doubt about that. You will receive in-state tuition here and will be in your home state. It, however, doesn't sound like you received any 'above the norm' offers or opportunities in this regard. UNC provides an outstanding education for primary care as well as others and the Triangle is a beautiful place to live.
Honestly, you can't really go wrong. But my personal opinion/what I would do is to take one of the truly unique opportunities placed infront of you by Wake and Miami. You're gonna make friends wherever you go and obviously, these schools REALLY want you. You've got 4 great years ahead, I think I go with the challenging and diverse option, whatever school that feels like to you. Let me know what you think of my advice and congratulations either way!