Not too big, not too small, the 1,070-passenger Crystal Serenity is the perfect size. Its spacious public rooms never feel cramped or crowded; the lovely tiered decks at the aft of the ship, plus the wraparound promenade deck, provide copious quiet spaces for sunbathing, reading, or napping. Meanwhile, inside there are multiple entertainment venues and dining options, including excellent Japanese and Italian restaurants. Scintillating lectures round out the activity options.

This modern interpretation of a classic ocean liner gets a lot of things right: The Queen Mary 2's elegant public rooms and cabins are generously sized, and the large library, planetarium, and numerous expert lectures are standouts. You’d never guess this ship can carry more than 2,000 passengers, especially if you occupy the top suites and can patronize the exclusive Grills Restaurants and its private lounge and deck space.

Nothing is over-the-top or bland here. Amsterdam hits all the right notes with its gorgeous artwork, much of it reflecting the line’s maritime history in paintings and murals. This appealing 1,380-passenger ship (sister to the Rotterdam) is a comfortable size with four dining venues, multiple entertainment lounges, and computer and photo-taking workshops. The 2000-built ship has come out of a recent dry dock and looks better than ever.

Large in size, yes, but the Grand Princess is also big on intimate spaces that easily make you forget it can carry more than 2,600 passengers. From the cozy atrium pizzeria and the three main dining rooms where you can dine when you wish, to the way the buffet restaurant offerings are divided into separate stations, everything about the ship feels small-scale. There’s something vaguely and appealingly nostalgic about it, from the romantic Crooner’s Lounge for live piano music and the classical repertoire featured in the atrium, to the wraparound outdoor promenade deck that's perfect for old-fashioned strolls.

These identical twins are comfortable overgrown yachts with lots of wood and brass detailing. The sunbeds, Top of the Yacht Bar, and al fresco dining keep most passengers up on deck enjoying the sun and casual, sophisticated mood. Your fare on SeaDream I and SeaDream II includes all wine and spirits, so a nice glass of whatever you're craving is always on hand to complement the delicious food and Riviera vibe. Water activities are easily accessible from the ships' stern marinas, and most itineraries stop at a port each day, which keeps things interesting and active.

Casually elegant, this 226-passenger ship excels in its French and continental food. The exquisite (and large) hotel-like cabins have a great bathroom design (toilet in one room, shower in the other). The decor is grown-up without feeling stuffy; service is sharp but not cloying or too formal — just the way its mostly European passengers like it. Your fare include spirits, wine, and soft drinks.

Pretend you’re not at sea at all (more like in a city) on this brand-new 4,248-passenger ship. You'll find more than 20 dining venues on Norwegian Escape, from seafood to burgers, so you’ll never have to dine next to the same strangers twice, or be stuck eating the same foods in a handful of similar venues. The 21 bars and lounges, thrilling waterslides, and challenging ropes course are further evidence that this ship is anything but typical.

Surprisingly, Disney Wonder and Disney Magic are not just for kids — there are pockets of elegance and serenity everywhere. And if you're not a fan of the noisy casinos and bars found on other big cruises, you're in luck; the adults-only entertainment lounges and bars on these ships are lively in a low-key way, and hit all the right notes.

This five-masted tall ship is an impressive historical throwback infused with lots of modern luxuries. The 228-passenger vessel features a mini spa and gym, three small pools, and comfy cabins, 14 of them suites. Under full sail, the ship is a sight to behold, and so are the itineraries: Royal Clipper makes daily calls to some of the most desirable corners of Europe and the Caribbean.

Radiance of the Seas is tiny compared to the line’s newest megas, but the upscale, 2,100-passenger ship is big on design, with lots of wood tones, warm colors, and intriguing art. There are no wacky waterslides or ice-skating rinks; instead you'll find spaces like the Colony Club with its self-leveling pool tables and the top-deck Viking Crown lounge with its stunning views through glass walls. Multiple dining options include a Brazilian steakhouse and Italian, Japanese, and Mexican restaurants, plus close to 20 bars and lounges for live cabaret and music.