Yay for this thread... I saw the title of it come up in the lounge and remembered a song I used to love.
It's a dance song but the most memorable part for me was the piano intro. I don't know why but it just gives me a sad vibe, I wish I could find a non-dance version of it.
YouTube - Robert Miles - Children
EDIT - I found an orchestral version!
http://www.youtube.com/watch?v=kPx8WroWGXg