For beautiful harmonies, I love
The First Nöel
Silent Night and
Angels We Have Heard On High

Other religious favorites:
Mary's Boy Child
Virgin Mary (Had A Little Baby)
What Child Is This?
God Rest Ye Merry, Gentlemen
There's A Song In The Air
Go Tell It On the Mountain
Ave Maria; Cantique de Nöel
Stille Nacht (Noche de Paz)
Gesu, Bambino
Es Ist Ein' Ros'
Still, Still, Still
Mary, Did You Know?
Follow, Now, O Shepherds

Genie