I've seen a couple of these places and think this is one of those lists made by somebody trying to sell an article. I definitely respect Nick Sanders experience and can see why he might think the coast of Britain and Alaska should be in a top 10. But saying "best roads" is a lot like asking what any individual thinks is best.
I'd love to:
Go back and see a LOT more of the coast of Japan. This place is bucket-list beautiful, the people are super friendly to us Gaijin, and it's clean and orderly.
Spend a summer month riding Norway again. Like Japan, it's an expensive place but worth being on anybody's bucket list.
South Africa has big areas I want to see more of, especially along the coasts. Capetown is one of my favorite cities in the world. btw - Finding quick lodging with AirBnB worked great and sure beat the hotels.
Go back to spend riding till bored with the Pyrenee, Alps and podunking all the little mountain-side villages along the French/Italian border area that you can't take a car to and don't want a big bike, but are great on middle-weights like the Honda 600 I had last time.
Ride Greece and up thru Croatia till I get bored. Till COVID that was part of the plan for this summer.
Riding scooters in the area of Dalian China was great and I'd LOVE to go back to explore more. It's photographers heaven and you'd be shocked at how many guys have actual motorcycles, not just scooters. Think what you want of the politics, China has some beautiful and cool places, plus I've had great times every time I've been there, interacting with everybody from Government officials to shop-keepers and local police. Unfortunately with the new law, how much I've worked in Taiwan, and something that happened post-retirement with my business, for me personally to go back now would not be a smart move.
Explore the Aussie and Kiwi coasts, especially on the NZ Southern Island. (That's really at least three places).
And just here in the US and Canada:
Ride more of the roads near the Canadian Icefields Parkway. Just like the Rt 129 Dragon Tail, the Icefields Parkway itself has become pretty touristy, yet everybody misses how many equally stunning roads and snow capped mountains there are to explore.
Go back to long parts of the Pacific US coastline on Route 1 that should be on anybody's Top 10.
There are stunning places all over the US Rockies for breathtaking views and rides. Utah has great memories.
California has multiple Top 10 lists by itself.
The Appalachians up into New England were made for motorcycles.
Everybody should see Nova Scotia, PEI, Labrador, and as much of the Atlantic coast up there as possible. Friendly people, stunning sights, and great hiking when you want to do something different.
That's way more than 10 already, I am totally aware how blessed I've been to see so much already, yet the list just goes on and on . . .