Seattle Central Library - 11 floors of awesome architecture and design. The kids book room is bigger than some WHOLE libraries that I've been to. Been there four times and still haven't seen most of it!
The moving platform in Rem Koolhaas’s Maison à Bordeaux allows the inhabitant to access a series of different levels that are stacked on top of one another. The movement of a central elevator continuously changes the architecture of the house.