A couple that we've stayed at over the years, but are on the North end between Pigeon Forge & Sevierville. if you like the outlet malls, DollyWood, Governor's Crossing, musical dinner theaters, then these are good locations. If you're wanting to get right into the Gatlinburg & Smokey Mts. then you may want something closer to Gatlinburg. Traffic in the summer going from these sites to Gatlinburg & park can be extremely slow & congested depending upon time of the day.
This one down along the river with a variety of nice spots that have been pretty level. We've been there about 4 times in the last few years and like it.
http://www.riverplantationrv.com/
We've stayed at the following a couple of times, it's top of the line for camping, if you're pulling a 5er or TT you'll have to back into the site, only motorhomes can use the riverfront sites, but the view is gorgeous and there are gazeboes set up for all campers to use.
http://www.tworiversrvresort.com/
Enjoy your visit, it's a great destination.
Victor