Called the "Housemaster" presumably because it resembles a house (or a modern Barbie Dreamhouse sans elevator), this Haba shelf unit offers a lot of versatility. Because the shelves can be accessed on all sides, it can be usefully positioned in several ways and could also be used to divide space within a room. This potential for flexibility makes it a perfect candidate for casters in our mind, but, alas, you'd have to perform your own hack for that added functionality.
This unit might be just the thing for young roommates looking for an equitable division of space. Even the top is designed to be used as storage for infrequently used items. Made in Germany (but available in the U.S.), it's not cheap - about $700. Available here.