Viking Ocean Cruises is the oceangoing line by the team behind Viking River Cruises. Launched in spring 2015, the ocean cruise ships take some of the most notable aspects of the river voyages and offer them at sea. First off, the ships are more all-inclusive than their competitors, with Wi-Fi, alcohol, specialty restaurants, and some shore excursions incorporated into the fares. There are other similarities too — headphones are waiting in your cabin on arrival for use on guided city walking tours, and you'll find plenty of modern Scandinavian design details, from blonde wood to furniture with clean lines. Read our full line review.

Celebrity has some of the most beautiful and best-designed ships in the industry, true contemporary stunners. Everything — from the extraordinary spa facilities to the half-acre of grass on the line's Solstice-class ships, to the martini bars and romantic seating areas with egg-shaped chairs and daybeds — is tasteful with a modern edge. It's a design aesthetic that has influenced the rest of the industry, too, and now ships are popping up on other lines with style choices that seem ripped right from Solstice. Read our full line review.
 

Formed by Royal Caribbean in 2007, the line’s two ships, the 697-guest Azamara Quest and Azamara Journey, have a country club casual dress code and relatively small staterooms. Think of this as "luxury light" at sea: The onboard experience has some of the hallmarks of luxury ships — including excellent food and service and an elegant ambience — without the matching price tag. Read our full line review.
 

This line may have been made famous by the TV show “The Love Boat,” but it isn’t just for honeymooners and singles looking to make connections. Instead, while Princess does try to offer a romantic experience for couples, these large mainstream ships also aim to appeal to the widest range of age groups. While there's little that's innovative here, everything from food to service and even design is well executed and tasteful on board. The ships themselves are pretty, with plenty of light, modern decor, and activities that range from computer classes to wine tastings and needlepoint. Read our full line review.

Oceania Cruises started out with three ships that had been part of the Renaissance fleet, and later added two larger new builds that redefined the line. The two classes are very different from one another: The older ships are intimate and traditional with plenty of dark wood and heavy drapes, while the new ships are elegant and modern — in an industry full of flash, they're downright residential and unusually tasteful, with recessed lighting, crown molding, and a subdued color palette. Throughout these ships, there's a focus on art and food that serves sophisticated travelers well. Read our full line review.

The line's eponymous luxury vessel has made Papeete, Tahiti, its homeport since it began sailing the lagoons in 1998. Owned by Pacific Beachcomber, which operates luxury resorts in the region (including The Brando, the eco-friendly getaway on an island once owned by actor Marlon Brando), the line focuses on the South Pacific. Read our full line review.
 

Holland America Line attracts scores of devoted fans who love the grown-up-focused experience on board. Entertainment centers on what a mainstream, slightly older crowd would enjoy: The line has hosted “Dancing With the Stars” celebrities and musicians straight from B.B. King’s nightclub in Memphis, Tennessee, and a partnership with Manhattan’s Lincoln Center brings classical musicians on board the line’s Koningsdam ship. Passengers appreciate the little extras, too, from complimentary hot appetizers during the very much observed pre-dinner cocktail hour — at bars all over the ship — to free tote bags for all passengers. Read our full line review.
 

SeaDream Yacht Club prides itself in providing a small-ship experience closer to yachting than what you find on other lines. You'll sail with 100 or so other guests, and the identical ships — appropriately named SeaDream I and SeaDream II — have a carefree atmosphere and a resort casual dress code. The food is delicious, the wine is free-flowing (and complimentary!), the piano bar is usually packed, and caviar and Champagne are served on the beach. What’s not to love? Read our full line review.