I was going to say this isn't the definitive list... and add a few... but it's quite there!
These are the ones I've done
1. Stelvio Pass Road, Italy
4. Col de Turini, France
11. Atlas Mountains Road, Morocco
13. Grimsel Pass, Switzerland
14. Road, Sahara Desert (part of! got hit by a lorry... trying again this year)
I would add some roads in Sierra Leone, Somalia and Australia..... oh and the Dalton Highway in Alaska... oh, and the transfagarasan in Romania if we're scared of hairpin turns!....
but it's quite a good list!
M.