Quite a few effing idiot secular humanists in this thread nominating "holiday songs" for a CHRISTMAS list. Try again, go-to-hellers.
My vote: "Away in a Manager"...preferably a version sung by a elementary school child. Factually accurate, and emotionally stirring.
Second place: "We Three Kings"...preferably sung by Burt Bachrach. Again, factually accruate, and the baritone delivery conveys the solumn dignity of this imporant nativity event.