Vacation, it's hard to give you answers because so much of a recommendation depends on things we don't know about you. This is one reason it's good to work with a travel agent, who can get to know your wishes and expectations, and recommend the right cruise line and ship for you.
Some things it would be helpful to know: have you been to Europe before? Are there places besides France and Italy you already know you want to see? Where in France and Italy? How much time and money do you have to spend on this vacation? What's your age bracket? Are you traveling alone, with one other person, or as a family? etc etc.
That being said, folks here can make some general recommendations, but as you can see, working with an agent who can hear the answers to those and other questions, and base his or her recommendations on those answers, will be better able to match you up with the right vacation for you.