I used to do the Dragon every year, either as part of Miatas at the Gap or Minis at the Dragon. The last couple of years have been less than enjoyable, in no small part due to TN Law Enforcement- their presence from the state line on makes it nearly impossible to enjoy the drive- even at legal speeds. I prefer Cherohala Skyway these days.
Another fun road- ok, a couple of fun roads- are:
1. US-74 Alt from Bat Cave NC to Asheville
2. Pinnacle Mt. Road, just outside of Flat Rock NC. There's a great apple orchard (Skytop Orchard) with the best apple cider and apple doughnuts, then a great drive on the road.