If "The Dragon" is on your list, you might need to get out more!
I wouldn't presume to have travelled enough mountain highways to claim to know any of the top-10 in the US, but I have ridden quite a few of those mentioned in Arkansas, some in The Smokies and a few in The Rockies. I would say my favorite was probably Black Canyon of The Gunnison, but the Million Dollar Highway was pretty good too, as was the road (whose designation I don't recall) heading East out of Taos. Have also been on a lot of great roads in Northern California and WV (all by cage). My very favorite roads are not in the US.