Carnival Cruise Lines says we all know one. You know, the dad who gets his nails done with his daughters or the friend who photobombs your cute couple picture. The mom who unashamedly blocks basketball shots when playing with children or the bride who tosses herself into the pool instead of her bouquet. Carnival calls these people, "The Fun Ones," and invites all of those who self-identify as a (or who want to be around) Fun One to book a cruise with it. Carnival Cruises start at $389 per person for a double-occupancy cabin.