I was waiting for my car to be serviced in Marietta, so I used Tripadvisor to find a coffee/tea spot in Columbia. Garth Café was the only choice within miles. It's a wonderful place. Cleon, the proprietor, personally served me and brewed a fresh pot. The atmosphere is relaxing in the large upstairs room, with views of the nearby historic neighborhood by the Susquehanna River. The café is furnished with upholstered chairs and sodas, as well as chairs and tables. Decoration includes works of art from the gallery downstairs. WiFi, too.
If you want a busy Starbucks, this is not the place. If you want quiet conversation in a great atmosphere, Garth Café is the place to be in Columbia.