So much to do here! We opted for the island of Capri, a jewel set in the Bay of Naples. Easy to take a fast boat on our own from where the cruise ship docks (5 minute walk). The only problem is that Capri can get overrun by tourists. It's still a wonderful place. I've been Pompeii before so didn't go this time, but it's a great trip.
We took the bus from ville france very easy and only a 20 minute trip. We strolled along the water, ate at wonderful cafes, and drank in the South of France culture. Hard to top this port for ambiance. Ville France is nice too, very quaint.
Easy train trip from the port to Rome, only 45 minutes or so. Rome is magical. My advice is to choose a few areas and focus. A lifetime is not enough to do it all! We did the Spanish Steps and the Trevi fountain, had a wonderful lunch and explored the shops. Don't overdo it!