Peter Hollens, "The Parting Glass". One of the true greats among all folk songs. We know that some version of it existed by the very early seventeenth century, because we have quotations from it in letters and the like; it was first printed in full in the eighteenth century, and very few things have had its staying power. It captures almost perfectly part of human experience itself, a small part, but a genuine part. My favorite version is still George Donaldson's, but this one works fairly well.