Let's face it: Pizza is one of the most loved foods in existence. It's versatile, it doesn't take a long time to prepare, it's easy to eat on the go and you can enjoy it for breakfast, lunch, dinner or middle-of-the-night snacking. Although it's difficult to make truly bad pizza, it's equally hard to make it stand out. Some cruise lines have managed to nail it, however. Below is our list of the best pizza at sea.