I believe mine would have to be Marianne Faithfull, specifically 'Come and Stay with me' which is, to my recollection, the first song I have ever heard. Even though it was released so long ago, it's beauty has lasted throughout the decades, and when the time comes I assume centuries as well.
(I'd post a link but it seems I am being virtually bound to this message board only until I make 15 posts
)