On my September road trip, I walked into the special regulation section of the Jackson in the Hidden Valley area. Trip report over on the blog (link below).
This place is the best water I have found in Virginia so far. Given that I live in Northern VA, I have not had the opportunity to get to the far southwest corner and check out the Holston and other spots over there. Hopefully, the farther away from the nightmare of the DC area you go, the better it gets.
It's an easy 1.7 mile hike to get back to the start of the special reg area. It's clean and unlittered with a nice wide river bed full of deeper pockets that hide good numbers of rock bass, smallies, thousands of bluegills, and even some trout that late in the year. The trees have just the right amount of standoff to keep from harvesting a flock of your flies, the wading is pretty easy, and the scenery is just great.
A bonus is that the non-special reg section that you have to walk past is pretty good as well. I saw plenty of trout tooling around in the clear water. I hooked up with the smallies, gills and rock bass but could not convince the trout to smack anything.
I worked pretty much everything - nymphs, streamers, poppers, terrestrials. Thinking back, I'll bet I did not have the nymphs dragging close enough to the bottom - but the smallie action was so good on top that I tended to forget about the trout.
Granted, I was there on a Tuesday which limited the crowds - I was the only truck in the parking lot - so I am sure that colored my perspective. I have heard that the Jackson gets busy, just like other water, when the stock truck makes the rounds. But given my day, it probably does not matter when you go - you'll have a good time. So, wait for the crowds to die down and then make a visit.