What song should I play???

I'm a really good eighth grade tuba player. My school has a talent show every year, and since this is my last year in the middle school I figure I'd try it out. I want to play my tuba, but I don't know what song to do. I want to do a pretty hard piece[to impress the judges] that everybody in the school would know. I don't want it to be like Mozart #5 in G Minor, etc, but a laid back and fun piece for me and the audience. Any suggestions please. Thank You!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!…