Roads aren't scary, conditions can soon alter that though, but that's more to do with the weather than the road.
There are a few "interesting" ones I can think of though , especially when in a 30 ft RV !
In no particular order.
Priests grade, [CA120] the old road especially.
Trail ridge road in RMNP.
Loveland pass, US 6 Colorado.
Southern end of the Generals highway in Sequoia NP . Recommended vehicle lenght of 22ft
And of course, The Moki dugway
The wife and DIL strongly disagree that there are no scary roads !! Lol
(I also put a copy of this video clip on this Route article...)