Based on personal experience I can recommend all of companies. I am planning to use some of them again myself I was so happy!
Rome and Naples- I used RomeCabs. Stefano was amazing to work with during the booking process. Both tours were great! They helped with entry tickets to our sites. Booked additional private guide at the Vatican and Pompeii. Which BTW, I would not do either without!!! (Actually due to a horrible rain storm in Naples we ended up canceling the guide in Pompeii, leaving my kids & mom in van with the driver for a quick Pompeii stop. We got terribly lost and really didn't see the key things I wanted to see. Not a memorable moment. I know had the rain storm not happened it would have been much better with a guide) The guide we had at the Vatican was terrific!
Villefranche- I used Revelation Tours. Of all my tours this was not my favorite. The guide was good but not great. She took us for a drive through Monte Carlo, a stop at Monaco for the Palace, Oceanographic Museum & lunch, then off to the hillside towns and a final stop in Nice. Monaco was amazing and I would recommend it again. The other I could skip. Put it this way when we go back I will be going to Monaco and probably nowhere else. For those that might wonder taking the time to inside the Oceanographic Museum is worth it. My whole family loved and my kids still talk about it.
La Spezia-I used RomeConnection. AWESOME! As a matter of fact I have already emailed then and FB'd my guide from last time to see if they were available. This one was a bit more expensive but worth every single penny. This was having a guide with you the whole way. When we went in the museums our guide went too. Showing and telling us everything that we needed to know to truly enjoy our tour. Strongly recommend these folks for your tours.
Barcelona - I used Barcelona Tour Guides. When we went we went in & out of Barcelona so I had them pick us up at the pier at the end of the cruise. We started out on a driving tour of the city seeing all the sites you need to see by car. We stopped at our hotel around lunch time, checked-in, dropped off luggage and then headed out for lunch and walking tour. Our guide took us to a local place for lunch, which was amazing! (Until I got home and saw the exchange and lunch for over $400 US... but I would do it again!) Then we went for a walking tour of the Gothic Quarter. Much of it cannot be seen by car/van and you need to have someone who knows their way around.
Hotels in Barcelona - On the way there we stayed at the Hotel Arts.
It was the James Bond Hotel! We booked the rooms through Virtuoso. Suites were cheaper than regular rooms and with a party of 5 we had 2. With Virtuoso you are guaranteed a FREE upgrade if one is available. So upon check-in we were upgraded to 2 floor apartment with butler service. This place was amazing!!!! They also sent a driver to the airport to meet us which made getting in off a long flight in a foreign country super easy. Now... Don't get me wrong it was not cheap. But it was an experience of a lifetime! Did I mention the pool??? It did not disappoint either!!!
Then on the tail end of the trip we stayed at the Petit Museum Palace Hotel off the La Rambla for a considerably lower amount than the Hotel Arts. It was your typical European Hotel. It was clean, reasonable, reasonable for off number of people and I felt secure. Everything you need!
If I can help with any questions or any additional info please do not hesitate to ask. As a first timer I asked a ton of questions and I feel blessed to be repeating and able to share my experience!
) Johnny Quest's first name is Jim and Iron Man is Mark. 
