I've really tried to love Let it Snow, but Joy remains superior in every way IMO. Arif Mardin really brought out the best in her, especially considering it was recorded in the midst of the Spirit tour.
We listen to both often, and not just this time of year! I'm just as likely to hear them in [insert random month here] as December. Georgianna's just giddy about everything Christmas 24/7/365: Music, movies, all of it.