I have only done three cruises. My first was on Celebrity Millennium in Europe, which was astonishing. My second was on Carnival Jubilee, which was astonishingly poor. My third was back with Celebrity, on the Century.
Friends, I cannot stress enough how well Celebrity does cruises. They really try to make it the best experience possible. The food was always excellent, the ships are spotless, and the service is as good as you get anywhere.
Before I go into any details here, some advice: Get in a day early, leave a day or two later. So many people on these ships do a fly in/fly out deal, which is awful for two reasons. First, you miss one of the ports of call entirely. Second, when I get off these ships I need at least a day for my balance to return to land conditions. I can't imagine getting on a plane with my head still thinking it was at sea.