Try playing this pattern on the snare drum for 15 minutes straight. Starting at pianissimo and ending at fortissimo. It's basically a 15 minute crescendo. Ah, college memories.... <iframe width="420" height="315" src="http://www.youtube.com/embed/LWcpw3GAAms" frameborder="0" allowfullscreen></iframe> It's so difficult, they actually made sticks specifically for performing this piece. Spoiler
Back in the beginning of my orchestra playing days, William Hofeldt's Lullaby was my favorite. That was way back in middle school. It was easy, but touching. A fellow orchestra student (alumni) at my high school wrote this song when his friend, a girl from the school band, passed away. I think they were pretty close friends. I had the honor of being among the first to hear this song live at one of our mid-semester concerts. I think this piece was meant for the piano and strings. This is the only version I can find, and it totally sucks compared to the real thing. We all cried at the audience when the composer played the piano for this. It was a very moving piece: <iframe width="560" height="315" src="http://www.youtube.com/embed/j1n-br9yur0" frameborder="0" allowfullscreen></iframe> On another note, Palladio (the old "diamond" commercial) is probably one of the most fun pieces out there for intermediate level orchestras. That and the Ho Down. One more, sorry... Variations of a Sea Chantey (used often on official NFL clips) is fun as well.