Cruising is pretty hot right now. My favourite was on a Holland America a few years ago now. It was 2 weeks from Rome to South Hampton. It travelled around the Med and made its way visiting Italy, Monaco, France, Spain, Belgium, Netherlands. We cruised at night and there was a port every morning. We only had a day in each port, not really enough time to do much so we decided that we would shop in the morning and find a great piazza/square in at around lunch time to eat and drink and watch the locals until departure. It was FANTASTIC. I am waiting for them to do a similar cruise again.