We all know that we are trying to ballance too little time and so much to see. Here is an idea, take a map of IIaly and a guide book such as Rough Guide or Cadogans, and a book such as The Most Beautiful Villages in Tuscany. Start reading, and highlight the towns that really grab your attention on the map. After a while you will have clusters, and you can then allocate your time accordingly. Don't loose sleep over what you are going to miss, but make sure you allocate enough time to see a smaller number of places in a relaxed state rather than trying to tear around and see everything. I guess this is pretty obvious, and you are hoping for advise on what we regard as the must sees.

Given two weeks, I'd spend three days in Venice, Florence and Rome. That only leaves five days. I'd spend them driving from Florence to Lucca and Pisa for a day, to San Gimignano, Radda and Siena over two days, a day around Montalcino or Montepulciano and the final day driving to Rome via southern Tuscany and down the coast with a stop at Tarquinia on the way.

Cheers Gavin