For me, Christmas isn't Christmas without at least one reading of Truman Capote's "A Christmas Memory," preferably with a audience willing to let me read it aloud. I enjoy "The Gift of the Magi," and for a laugh, Steve Martin's parody, "The Gift of the Magi Indian Giver," in his collection Cruel Shoes. At some point, someone will read the Christmas story from the Gospel of Luke.
I'd love other suggestions of favorite Christmas books and poems, particularly some that would be perfect to share around the family holiday table. I can't pass up a captive audience in a holiday mood.