Staterooms on Serenade of the Seas run the virtual gamut - from cozy-yet-basic inside cabins to way-over-the-top grand suites (complete with piano!).
Standard cabins (balconies, outside, inside) feature the usual layout and amenities - no surprises there except there are few bathroom amenities (beyond shampoo in a dispenser). The bathrooms are shower-only in these staterooms. We liked the idea of the family suites - there are two different types, one with a living room and two bedrooms, the other with one large room (with bed and sofa) and a small bedroom - but weren't crazy about the layout (bedrooms were windowless in some cases). Royal Caribbean is definitely trying hard to encourage passengers to upgrade to its suites - and in some cases it's definitely worth the extra cash. Suite holders, in addition to getting more room, receive more amenities (bath products, whirlpool tubs, CD players, access to Concierge Lounge) though you'll also pay out a big chunk of cash for the privilege.
One interesting (and good value) in-between (standard verandah and full-fledged suite) alternative is the junior suite. For about $100 more (per person, double) than a standard balcony cabin, you get much more space - both inside and on the verandah -- and a more expansive bathroom (with tub). However, residents of the junior suite do not qualify for any other "official" suite upgrades, such as use of the concierge service.
In all cabins, RCTV, the cruise line's interactive television, offers a first-rate range of channels. There are plenty of movies (free and pay-per-view) - including a daily "classic" selection and we loved channels that ranged from CNN to RetroTV (terrific for catching up on all those "Partridge Family" episodes you missed!). There's an in-room reservations system that can book everything from room service to shore excursions (though you may want to make important reservations over the phone, as we had some challenges with bookings made - yet never received. Other passengers reported similar experiences). There's also a hair dryer and mini safe, and room service is available around the clock.
A couple of points worth noting: As with most new ships these days, standard cabins feature a mere two electrical outlets. And a few caveats to keep in mind when booking: cabins 1598, 1098, 9252, 9652, 8662, 8162, and 8164 have partially obstructed views. On some standard balcony cabins on deck seven, which are adjacent to the roof over the tenders, the sun can reflect off the tender deck; this can make the verandah feel pretty sweltering - especially on temperate Caribbean itineraries.