The only time I listen to classical music is when I am working as I find it soothing but not distracting. I don't have a vast amount in my collection but one piece always makes me stop for a moment.
For me it is just as much about the pauses as it is the notes being played; it's as if the music is spontaneous almost like a train of thought or stream of consciousness from the pianist and that makes it, for me, such an arresting piece.
I never tire of hearing it, it's Debussy's Suite Bergamasque from Clair du Lune.
Download 01 Suite bergamasque_ Clair de lune