Eudora Welty wrote the best Christmas story I know, A Worn Path .
Welty's ability to imagine the mind and world of the central character makes the story a masterpiece of empathetic understanding. The apparently simple story is like a complete exposition of everything that Chrismas is supposed to be about.
Looking for it online, I found a movie that her publisher made of it, which is remarkably faithful to the original and which presents a really great performance by Cora Lee Day as Phoenix.
A Worn Path
Interview with Eudora Welty on the story.