I live down the street from Coastal GA RV Resort in Brunswick, GA. It is a new park, all asphalt and concrete with some saplings between sites that will offer some privacy in a handful of years when they get taller. One of the owners lives on site and is always out and about. They get pretty crowded in the winter, so you might want to talk to them if you haven't already. The resort borders a private lake with pretty decent fishing. I doubt any water front sites would be available.
The only real downside to Coastal GA RV Resort is that it is only about 2 miles from I-95 and you will hear it from time to time. You can walk to the liquor store and Dollar General just down the road and you are less than 2 miles from the nearest Supermarket (Winn Dixie).
Blythe Island Regional Park and Campground (same I95 exit as Coastal GA RV Resort) is more like a state park with heavy tree cover and semi-private camp sites. It's about $150 - $200 cheaper a month than Coastal RV Resort and it is quieter. Blythe Island has a small lake with okay fishing (pay to catch and release fish) and it is on the South Brunswick River with a fishing pier and boat launch. Last winter they were at most half booked at any one time.
Edited to Add:
Jekyll Island Campground (same exit as the two above) is an okay campground. We've stayed their once, would not do it again. About the only thing going for it is that it is on Jekyll Island. We love Jekyll Island (we go often for the day with our MH), but the campground is not as nice as either of the above campgrounds.
Their are no amenities other than WiFi. If you like to bicycle and/or walk this would be the place for you. I drive to the Jekyll Island Welcome Center (just before the toll booth) and bike onto the island. You can safely bike around and across the island for about a 20 mile bike ride. If you plan to leave the island, you will need to get a parking permit. You'd need an annual pass which is $45 ($90 for oversize vehicles - anything over 8 feet tall). Otherwise it is $6/day (I forget the weekly rate, but I think it is $25).
-Michael