One I absolutely have to do before I go, Route 12 in Utah. Another one would be the million dollar highway in Colorado, don't remember the actual route number but I hear it's an amazing road.
DocLubo ... I'm in New York, give me a holler when you start planning, maybe I'll join you for that ride across the states!
I'll definately give out a shout if I do. I'm in North NJ close to NY State.
Over 60 now, and will have to do it soon or I may have to trade in for a trike LOL