Santa, please make me a waterproof karaoke machine, with built in shampoo and soap holder. With an LCD, and wifi that can stream (heh) new tracks down from some buying service. And the microphones should have pitch change, so I can sing both the Diana Ross and Lionel Richie parts of Endless Love. And it should have some sort of digital filter that makes gurgling noises sound like Pavarotti.
Extra points for making a showerhead that doubles as a microphone.