I think this interactive sculpture called Unnumbered Sparks(2014) put together by Janet Echelman and Aaron Koblin is absolutely stunning. What I admire most about this work is that it does not only visualize data to form incredibly beautiful patterns, but also continuously collect new data from visitors and simultaneously change its appearance according to it. Surprisingly, this entire project was built in Google Chrome with several web technologies. The sculpture itself is actually a web browser, and the lighting on it is a full screen Chrome window composed with more than 10 million pixels. Also, by using WebSockets, it allows the instantaneous collection of location data from a Smartphone/tablet devise to be later translated into visualization.
Link to the work: http://www.unnumberedsparks.com/