For mega resort fans, there's nothing quite like a Royal Caribbean vessel.
The line's biggest ships are more than 20% bigger than almost any others afloat and feature every type of amusement imaginable, from rock climbing walls and surfing pools to Broadway shows and ice skating rinks.
Families, in particular, will love this line. Royal Caribbean sails everywhere in the world, but its heaviest presence is in the Caribbean and Europe.
Multistory waterslides, ropes courses and even go-kart racetracks are among the gee-whiz attractions atop Norwegian Cruise Line's giant, resort-like ships. The vessels are also packed with eateries, bars, casinos, and showrooms.
The brand is known for its entertainment, including big Broadway shows such as "Beetlejuice." If you're looking for a Las Vegas-style resort at sea, this is your line.
Known for carefully crafted, globe-circling itineraries on midsize ships.
However, Holland America has been shaking things up in recent years with lively new venues such as B.B. King's Blues Club. Couples and retirees are the market for this line. Families with kids might want to look elsewhere.
Popular with middle-aged couples, retirees, and multigenerational families, the "Love Boat" line's ships aren't as flashy (or big) as those of Royal Caribbean and Norwegian, and that's just the way its customers like it.
Princess Cruises' customers also like its wide range of itineraries, including voyages in Asia and Australia, as well as closer-to-home places like the Caribbean. It's long been one of the dominant lines in the Alaska cruise market.
The self-described "fun ship" line is the king of short, affordable, fun-focused cruises from U.S. ports to the Caribbean, the Bahamas, Mexico, and beyond
A giant of cruising in Europe, Switzerland-based MSC Cruises is making a big play for North Americans with newer, bigger ships sailing year-round from Florida to the Caribbean and Bahamas. It also offers sailings from New York City.