Three favorites, again from my youth. "Hark! The Herald Angels Sing" is an English Christmas carol that first appeared in 1739 in the collection Hymns and Sacred Poems. The carol, based on Luke 2:14, tells of an angelic chorus singing praises to God.
"Away in a Manger" It was long claimed to be the work of German religious reformer Martin Luther, some Germans will not sing it, saying it used to be a beer drinking song. (at least the melody) If you imagine an Umm Pa Pa beat to it, you see their point. But this is a favorite in the English speaking world. 
"Run Run to the Stable" at least the version I know is an old French Carol. If you have heard it before, please leave a comment.