I started a new tradition last year, one that the kids and I are enjoying immensely.
Instead of using the classic Advent calendar to count down the days until Christmas, we have a stack of holiday and Winter-themed books all wrapped up, waiting to be opened and read, one per day.
I eliminated a few of the books from last year, for various reasons, and therefore got to add a few new titles. Based on some of your recommendations and my own searching, we added A Wish for Wings that Work by Berkely Breathed, Great Joy by Kate DiCamillo, Christmas Farm by Mary Lyn Ray, Just Right for Christmas by Birdie Black, and Owl Moon by Jane Yolen.
Advent Bookshelf over at Goodreads to see the complete list.