BBQ between Columbia and Charleston
I was planning to type Sweatman's until I read the body of your post.
If you are serious about BBQ, and you don't mind a bit of a detour, McCabe's BBQ in Manning is the place to go.
For far less of a detour, but with a pretty great southern buffet, including BBQ, in a historic location, go to Lonestar Barbecue in Santee.
Take Russell St. off Exit 149 in Orangeburg, SC or Matthews Rd. off Exit 145 on I 26. Either Russell or Matthews will take you to Chestnut then go right to get to Dukes. Take Matthews to Russell to Edisto Village Shopping Center or take Russell all the way to Edisto Village Shopping Center and Maurice's is on N side of Edisto Village.
Dukes BBQ @ 789 Chestnut Street, Orangeburg, SC 803 - 534 - 9418.
Maurice's Gourmet BBQ @ 1586 John C Calhoun Drive, Orangeburg, SC 803 - 516 - 8771.