I love our "doll house" ones. Wooden boxes that stand about 3' tall, 4" wide, with doors for each day, and you stick a part of the Scripture reading in them for each child, along with a better-and-better sweet or candy as Christmas approaches. Brings out the whole "something marvelous is coming from On High!" idea.
But now we're broke so we just use these beautiful "cards" (just as big) where the door opens for the scriptures. Book of Kells script on them; very beautiful. Gift from a parishioner years and years ago. It's beauty is stunning.
(I should sell the huge wooden ones on eBay! Huh, pay some bills!)