Royal Caribbean International, which was formerly known as Royal Caribbean Cruise Line when it was founded in 1968 in Norway, is one of the most popular cruise lines today. Having held the title of largest cruise ship in the world since 2006, they're known for their innovative ships filled from head-to-toe with thrilling activities.
They've also got some of the best entertainment at sea, with their Oasis Class ships allowing guests to watch Broadway-style musicals and high-diving acrobatic spectaculars at the AquaTheatre.