First-class, personalized service is just one of the hallmarks of luxury cruise lines. You can also expect exotic itineraries, varying degrees of inclusive in pricing, fine wines, and gourmet cuisine, as well as universally high crew-to-passenger ratios. Sometimes, you might think any old luxury cruise ship will do, but that's not quite true. Like people, cruise ships have their own unique personalities, and some will be more suited to your vacation style than others. Let's take a look at the world's best cruise ships.