Back when I was in high school it was Lady In Red.  I'm not entirely sure why... but any time I heard it I would turn it up and make sure no one was talking.  My mom bought me Simply Red's Greatest Hits thinking that he was the one who did the song.  I told her it was Chris DeBurgh but I liked Simply Red too.

These days I'd be hard pressed to pick one song out of the thousands and thousands I've heard, much less listen to with any regularity.  I suppose In The Sun by Peter Gabriel would be a fore runner.  I'll stick with that for today.