I've been down to the southern end of South Carolina several times with friends from Ohio and KY. A few of the finds (from a few years ago) include:

Mud Snake (Farancia abacura)

Scarlet Snake (Cemophora coccinea): this is a very small juvenile I found while walking over a trash heap. Its bright coloration makes it a beautiful snake, but they are nigh impossible for most people to keep in captivity, especially when they're smaller than a redworm. Take a picture, then release.

Southern Copperhead (Agkistrodon contortrix contortrix): These are fairly common. This juvenile was found under a piece of tin in a scrub area. They are venomous at any size.

Scarlet Kingsnake (Lampropeltis triangulum elapsoides): This was caught by Sean Trimbach while road crusing. It pretty much made his trip.

Redbelly Water Snake (Nerodia erythrogaster erythrogaster): This was caught as it lay on top of some branches over a creek, with a long pair of tongs off a bridge. This turned out to be the best pet watersnake I've ever had.