In addition to MJ's excellent list of sideways staterooms on the Classic ships (Magic / Dream), there are also four sideways suites: 8032, 8034, 8532, and 8534. My DW and I have stayed in 8534 on both the Wonder and the Magic – and on the Magic it was for the justly-famous 2010 WBTA, which was just amazing.
What makes these suites sideways suites is that they are squished by the elevator bank amidships. As a result, instead of being double-wide (i.e., as wide as two staterooms) and going from inboard to outboard, they are triple wide, and point from bow to stern. This results in a number of advantages:
1) You get a triple wide balcony. There are only 8 staterooms on the Classic ships that have triple (or wider) width: the two Disney suites (which have quadruple-width balconies), the two 2-bedroom suites (which have triple-wide balconies), and these 4 sideways 1-bedroom suites.
2) You get a HUGE living room instead of a long entry-way. Good trade!
3) If you have several people in your party, the Murphy bed pulls down in the living room instead of inside the bedroom. (OTOH, this would make it difficult to get out of the suite without climbing over the Murphy bed and pull-out couch. We figured that if we were ever in that situation, we'd go out and in on the balcony instead.) and
4) If you have either 8034 or 8534, you get the biggest walk-in closets on the whole ship, bigger even than in the Walt & Roy Disney suites. This is purely an accident, and has to do with the way the elevator banks intersect with these suites.
All told, they are our favourites – and other peoples' as well. I think these four suites go fastest – right after the two Disney suites.
And the best part about these suites is that my DW and I have one booked for the EBPC in 2014! Sweet!
Richard