Well, I don't know if they're the best, but definitely the most reasonably priced ribs are at the Trail's End Buffet at Fort Wilderness! It's a western-themed restaurant, serving ribs, chicken, corn on the cob, baked beans, etc, etc. The prices are reasonable and the food is very good!
It's also a fun place to spend a little time before or after dinner! There is a petting farm, pony rides, trading post, and hayrides in the evenings!
You can get there by bus from any of the parks, or by boat from the MK.