The most popular is probably 'A Christmas Carol'. It has been adapted into many movies and plays. People love it because it shows the transformation of a cold - hearted man into a kind and generous one.
Among the classic Christmas stories, 'Rudolph the Red - Nosed Reindeer' is quite popular. It has become a symbol of Christmas, with Rudolph leading Santa's sleigh. Also, 'Twas the Night Before Christmas' is beloved as it sets the mood for Christmas Eve with its descriptions of Santa Claus and his activities.