One of my favorite routes in all of Italy is around Mount Etna in Sicily. Most of the tourist buses head up the volcano from the opposite direction of this route in the morning, so they won't be in the way. After that cars are pretty much non existent. The road like a race track most of the way. ...
From the base of Mount Etna, the SS185 winds its way down to the coast through secluded villages. It gets rather narrow at times but its still an enjoyable ride.