In planning a route for the trip to Georgia in a few days, I remembered about the Great Smoky Mountains Expressway, which is Highway 441 from Gatlinburg, TN to Cherokee, NC. 
I drove this route on my way home from my sister's college graduation in Toccoa, GA, in 2004. It was the middle of the night, in my not-so-trusty Jeep Cherokee, with my new kitten, Scout, in tow.
I stopped for a picture of one of the road signs that night. This was just before a loop that crossed over itself. Here it is on Google Maps, though Google's a little confused on the correct way to traverse the spiral.
Driving 441 in my Jeep was fun, but not nearly as fun as it would be on a motorcycle (and in daylight). So it goes on my lists of roads I must ride before I die. James informs me of two others: Pigtail Bridge and Tunnel and Needles Highway. Add to that the Blue Ridge Parkway, suggested by Tori.
