Favorite Highway/scenic byway for cycling?

[XXtwindad]

Inspired by Charlie’s planned Highway 33 bike trip, I’m wondering what other scenic highways/byways are on the Bucket List?

I’ve done Going to the Sun Road once (Montana) and Highway 1 off Tam many times. Both immaculate. On the BL: North Cascades Highway between Winthrop and Marblemount (WA), The Blue Ridge Parkway (esp the stretch near Asheville NC) and the Kancamagus Highway. (NH)

On a related note, I’ve always been confused when a highway is bike legal. Or advisable.

P.S. I highly recommend the book with attached pic. Some great ideas in there.