Schumann's Davidbundlertanze! By far one of the most beautiful pieces for piano he ever wrote. I love it. Damien Luce plays it wonderfully on Youtube, check out the link: http://www.youtube.com/watch?v=eO7t8mczEUk
. If I remember correctly, it was one of the last pieces Schumann wrote, and an absolute masterpiece of beauty, passion, sorrow and joy melted into one. It's hard to play and I only learned parts of it. But playing it is so therapeutic and such a wonderful release. It was also made into a very famous ballet choreographed by the great George Balanchine in 1980. Watching the dancing and hearing the music was doubly exhilarating!