I really like the idea of making the holidays more about spending time together than about "getting stuff." Activities include: Make hot chocolate and stir with candy canes, Watch a christmas movie and eat popcorn, Go out for a Christmas treat, Do something nice for someone, Drive around and look for Christmas lights.
Wrap up twenty-five children's books and put them under the tree with a special blanket next to them. Before bed each evening, your kids choose one book to open and read together until Christmas. Love it! This might be better than an advent calendar!!