I am a bit of a Tour de France fan and so wanted to have cycled all the famous cols to experience it for myself. Not wanting to take years over it I looked into doing all the Alpine cols in as few days as possible. What I found out was that there route called La Route des Grandes Alpes which is promoted by the french tourist board: http://www.grande-traversee-alpes.com/je-voyage/par-la-route/la-route-des-grandes-alpes.html
It is recommended as an 8 day route and misses a couple of TdF classics like the Col de Joux Plane where Lance Armstrong was in all sorts of trouble ...