There are a lot of Christmas songs which have been done and redone by various artists over the years. Some renditions are a lot of fun, some are very powerful, others are just plain unbearable.
In the very powerful category we have Mahalia Jackson singing, well, anything. Her version of Oh Holy Night brings tears to my eyes. It is a song I will forever associate with my Dad- he plays it over and over every Christmas, and he loves her version the best.
I found a copy of it on Youtube, but the video isn't the best, but the song is worth it.