29. "Lux Aeterna (Winter)" by Clint Mansell & Kronos Quartet
Another soundtrack song (from the gorgeous and scary Requiem for a Dream), and a movie-trailer regular, this has, to me anyway, become almost as iconic a piece as anything by Beethoven or Mozart. I know that's a bold statement, but I stick to it (this is my opinion, go write your own list!). Mansell and Kronos Quartet created a musical theme for a film that became so much more than just a theme for a film. It's timeless and beautiful and full of power and sadness. It, quite simply, moves me.