Let's just go to MOAB... lol jk
I know my opinion doesn't matter as much as I'm still in my n00b stages here, but here's my .02.
At first I was going to suggest Windrock and combining the ATRu, but then I saw how ridiculously expensive the registration for that was, of course, I know we don't have to register for it. I still wouldn't be opposed to this option as Windrock isn't too far away for us. We went for GSMTR and loved it. We only wheeled one day as I kinda put a little smackdown on my t-case and killed it for the weekend, but aside from that, the one day we wheeled, the trails seemed to be awesome. Definitely seemed to be a very good variety of things to do from crazy stuff for built rigs to mild stuff for the folks who need to drive home after a good weekend of wheeling.
I'm indifferent on Harlan. That was our first big wheeling trip. All we had done beforehand were bunny trails up in the mtns here, so we didn't wheel too terribly hard while we were there. I'm sure this time, if it is in Harlan, we'll hit some of the gnarlier trails as I've gotten a little more time under my belt and enjoy hitting some of the harder more technical stuff. With that being said, it is a fairly long drive (certainly not complaining, and I know some of the other folks drove farther than we did), and I also have to drive the rig back home, not to mention I've got a new job and have been promoted to the night shift manager, meaning A) I can't take any vacation yet as I haven't been there for a year and B) I don't get off until 10-11 which would mean we'd either leave at 1am and not be there until first thing in the morning or leave first thing in the morning and not be there until early afternoon. At that point we'd only have a day to a day and a half of wheeling, two days at the very most. Again, this is none of y'all's issues, and this is just my .02, but that may put us out for Harlan.
I have been wanting to check out Durhamtown Tellico for some time now, and from what I've just been recently reading on it, it seems like it'd be a viable option aside from the distance that the folks from farther up north would have to travel. I may even do some scouting up there here soon if I can make it up there!