The entire technical design--lights, sets, props, costumes--for
The Light in the Piazza was fantastic. I feel it all captured the essence of not only the novella, but of the real post-WWII Italy as well. I have never seen a more exquisite production.
However, the most awesome "set piece" I've ever seen wasn't on Broadway. It was at the Cap Rep Theater in Albany, NY, during a production of
The Grapes of Wrath. They had a water trench built into the stage, which they used for the Colorado River scene and the rain scene at the end of the show.
For the river scene, the Joad boys jumped in naked (which of course was awesome in and of itself) and then the slow one (forgot his name) literally walked off down the river.
For the rain scene, sheets of water poured down from above into the trench, while the dust bowl migrant men were rotated on a turntable that passed under the water.
I know that pools on stage aren't fantastically new or innovative, but for a small regional theater it was an amazing technical achievement.
On the road of life, do not pause for suicidal chipmunks who freeze in your headlights, seeking death by your tires...