Here are some of my latest favorites:

When Christmas Morn is Dawning - an old tune; we discussed it here; Wolfgang and several others helped with some history of the tune; Berit helped with the Swedish.

Christmas Comes But Once a Year - variant of Greensleeves; Masato found this one for me.

Il Est Ne (He is Born) at the cyberhymnal here.

Whence Comes This Rush of Wings here.

Rock-a-bye My Sweet Little Boy here.

I'm always looking for more, so please keep 'em coming.