The King
Cherry Tree Carol (the version we sing)
Holly and the Ivy (same here)
Almost anything sung by Nowell Sing We Clear

I'm also very fond of the melody for "Once In Royal David's City" but I don't find the words particularly exciting.

I also love the harmonies in "Silent Night" and someone back in the '60s did a great jazz version (on bass flute -- very low register) of "We Three Kings of Orient Are".

I always HAVE to sing the Walt Kelly's version of "Deck the Halls", at some point, too.

And --

"Joy to the world
Cuz cats are here.
They fill our hearts with joy.
Let every one
Prepare them food.
And let them eat their fill,
And let them eat their fill,
And let, and let, them eat their fill."

Linn

Linn