Christmas carols sung at my place last Saturday night:

Angels We Have Heard on High
Away in a Manger
The Boar's Head Carol
The Borning Day
The Carol of the Birds
Cherry Tree Carol
Coventry Carol
Deck the Halls With Boughs of Holly
The First Noel
Gaudete
God Rest You Merry, Gentlemen
Good King Wenceslas
Hark! The Herald Angels Sing
The Holly and the Ivy
Joy to the World
Mary's Boy Child
North Wind
O Come, All Ye Faithful
Once in Royal David's City
Shepherds Arise
Silent Night, Holy Night
The Twelve Days of Christmas
Virgin Mary Had a Baby Boy
Wassail Song
We Three Kings of Orient Are
We Wish You a Merry Christmas
What Child is This?
While Shepherds Watched Their Flocks By Night

We actually had about four different versions of "While Shepherds watched .." as we had someone who taught us several different South Yorkshire versions, with differing, though similar choruses.

If I had to pick a favourite, it would probably come down to "O Come, All Ye Faithful' or "Silent Night"