Lots of folks rave about 521 BBQ in Fort Mill, SC. I have eaten there and enjoyed but do not consider myself a Carolina BBQ expert. The subtlety is lost on a lout like me. I get fired up for Texas style BBQ. Beef with lots of smoke flavor is more to my liking.
If you have a little time on your hands you can go to Midway BBQ in Union, SC. Been around a long time and they offer a tomato based bbq as well as mustard based. They also have bbq hash and chicken stew. Fabulous!