In this game everyone sings their favorite carol at the same time! Great icebreaker.
Several prizes Pencils and paper
Have everyone write down their favorite Christmas carol, as long as it is NOT the Jingle Bells. Next have everyone write down five different numbers between 1-20 (depending on the group size). The host starts calling out numbers between 1-20 randomly (don't use the same number twice), and the people who have that number written on their paper have to sing the carol they wrote on their paper. Tell them no one has to sing solo, (and just the first line of their song). Pause slightly between numbers. After someone has all five numbers called out that they wrote down, they win...BUT...they have to stand up, sing jingle bells and laugh like Santa (Ho Ho Ho) to receive their prize. Be aware that several may win at the same time.
You can even start giving little prizes in the middle of the game for most pathetic singing, best solo, most original song, etc.