We were hoping to see a few more comments before we jumped in on this topic. There is no easy answer to the OPs queston as so much depends on personal preference. We have spent many months in Italy (driven more then 10,000 miles within that country) and also been there on numerous cruises to many ports. It is nearly the same with Greece (not as much driving) and we really enjoy both countries. But here are a few things for the OP to ponder. Carefully look at the various itineraries and pay a lot of attention to the amount of time in port as well as the days of the week in ports. For example, in Italy many places of interest are closed on Sundays and Mondays. In many cities you will find key museums closed on Monday or Tuesday. Some cruise lines allow too little time in certain ports..where it may take more then an hour to get from the port to key sites. And there are significant differences between various ports of the same country. A cruise that stops in Mykonos and Santorini might be great for those that like the Greek Island atmosphere...but others would probably prefer ports like Kusadasi and Naples where they can visit amazing archaelogical ruins. Some folks might want to visit larger cities (Rome, Paris, Istanbul, etc) while others might prefer gateway ports to smaller places such as Marseille or Cannes to get to Provence, Livorno or La Spezia to get to Cinque Terre...etc. There is no right or wrong...its just personal preference. We often suggest that folks consider European cruises that begin and end at different ports...and then you can extend your trip on both ends to have some land time in two different places. One of our neatest cruises was a ship that went from Civitavecchia (Rome) to Istanbul. We spent a couple of weeks in Italy before the cruise and a few days in Turkey after the cruise (yes, we know that not everyone has the time).
P.S. We will not sign or posts with previous cruises because we started to loss track after the first 60 or so cruises
. But could not help but notice the Alexander Pushkin in the previous posters signature. That would probably be an interesting story in its own right.