Exception: Carnival has several cabins which are classified as inside cabins but actually have a french glass door which allows light into the room (no balcony, but the door can be opened). Carnival also has some cabins that have a window, but because the window has an obstructed view (that means there is a railing or object in the way) it is listed as an inside cabin. Royal Caribbean has some cabins that have a window but look out over an inside promenade area. These are called "promenade staterooms".
Costa started the spa cabin trend, but many mainstream lines quickly followed suit. The concept is simple: Spa aficionados pay more for cabins decked out in Asian-inspired Zen decor that come with extra amenities, ranging from fancy showerheads and specialty bath products to fluffy bathrobes, yoga mats and healthier room service menus. Spa cabin residents are granted free access to spa restaurants (such as Celebrity s Blu or Costa s Ristorante Samsara), complimentary passes to spa pools and sauna/steam room areas, and may get free, discounted or priority spa treatments and fitness classes. And you do not always have to book a huge suite; on Holland America, several inside cabins have been designated as spa cabins with all the associated perks.
Having a personal butler can be a wonderfully pampering experience, and some cruise lines include the butler service as part of your fare when you select a suite or "concierge level" cabin. Look carefully at the difference in the cruise fare, and decide if it is really worth it. Beyond that, look at the services that are offered; some cruise line butlers really do provide extra value. For instance, some can bring you room service from hard-to-get-into alternative restaurants, refill your mini-bar to personal specifications, and serve in-cabin meals course-by-course. Butlers can also unpack and repack your bags, draw rose-petal baths and assist you in preparing in-suite cocktail parties.
Pay attention to the unique cabin setups on your ship, as they are not all created equal. Disneys four cruise ships, for example, have large standard staterooms designed to accommodate families. Even inside cabins may have a sleeping section that can be curtained off from the living area along with a split bath system. (One bathroom has the shower/tub and sink, another a toilet and sink.) Carnival is also known for having larger-than-average standard cabins, while Silversea, Regent Seven Seas Cruises and Seabourn ships feature all-suite accommodations. Norwegian Epic cabins sport the "new wave" design, with curvy walls and separate rooms for showers and toilets; sinks are located in the main cabins. As mentioned earlier, cabins at the very front and back of a ship often have different layouts than the cookie-cutter cabins that run the length of the ship.