We have booked with the Liberty on the july 7th sailing from Barcelona and are excited to try the freedom class.
We are first and foremost cruising because of the ships and the ports become second priority when booking a cruise.
Last year we went on the Grandeur out of Palma and visited amon other ports Naples which we will be returning to this year. As Dave and Lisa say, Naples is a gateway to other, more interesting sites like Capri or Pompeii / Vesuv. OR you can take a taxi to one of Naples' famous pizza places since the city is home of the pizza.
Like Naples, Civitaveccia is a gateway to Rome. We are not sure if we are going to Rome on this cruise since Rome in july can be a H O T experience when it comes to temperature. Im not sure if i like to spend a vacation day walking with a five year old son in crowded streets with a million other tourists when I instead can stay by an empty pool onboard :)
Villefranche takes you to this beautiful village or to Monaco or Nice on the french riviera. Always lots to there.
The other ports I know little about. Would like to see the tower in Pisa though :)