Directly on the Lake in GA Mountains

There is a campground on lake chatuge just outside Hiawassee on state hwy75 north.The campground is called ''Jack rabbit Mt.''just across the NC.state line.We camped there many times years ago.Many campsites right along the lake shore.Was a very nice and clean COE campground.
Also on lake Blue Ridge near the town of Morganton GA. There is a large campground known as Morganton Point Recreation Area.Camped there many times also, many lakefront sites,very nice area.Have not camped in either place for several years,we live in the immediate area and usually camp farther up in the Smokies now.Hope this helps.
Ramp

You may want to checkout the COE campgrounds on Lake Lanier and nearby SC lakes.

Check out Chatuge Woods. Chatuge Woods Campground - 2307 Red Banks Dr, Young Harris GA - 706-896-4012. It's located on Lake Chatuge off Hwy 17 going North from the junction off 76 toward Hayesville, NC. There's not a lot of info on the park online. Look at it on Google Earth & see if this is what you're looking for. We have friends who come to this cg every summer.
We have visited Poteet Creek in Union Co. It looks like a lot of permanents - or locals that leave their rigs & come out on the weekends. We saw no lakefront sites available. When you check the link shared by previous poster, you can always call & see what they have.
There's quite a number of cgs in the NE GA mtns - not all are on the lake, but others have quite the view!

http://www.unioncountyga.gov/Departments/ParksRecreation/PoteeteCreekCampground.aspx

Poteet Creek Campground on Lake Nottely. Union County Park. 59 sites, some lakefront.