TN, KY, and WV have great parks. The only bad thing about those states is getting a reservation!
Red River Gorge area in Kentucky is fabulous with several campgrounds: Red River Gorge Online
Natural Bridge State Resort Park, Slade, KY
Kentucky State Parks - Home
Another excellent state park near the 2nd highest peak in the eastern US (Roan Mountain right on the TN/NC line): TN State Parks: Roan Mountain State Park
Sad to say, the NC state parks are not very good. Stick to private campgrounds. South Carolina is better but hit or miss. Georgia parks generally seem rundown due to lack of maintenance...they were really nice 20 years ago.
2010 Flagstaff 829RGSS
Still to go: AK, NL, NT, NU, YT