When I was doing youth ministry in the 80's, we took the kids caroling door-to-door. Not collecting money, just bringing some Christmas spirit to the neighborhood. It was fun.
When I was a child, we always spent Christmas Eve at my aunt and uncle's. Everyone sang carols, with my uncle and a few of us cousins taking turns at the piano. Mostly we sang the common stuff, but my favorite was -- and still is -- Tu Scendi Dalle Stelle
(aka O Bambino
). Yes, this was the Italian side of the family.