This is one of the lucky days where I happened upon a good Snape fic before I even started looking for one... Speaking of which, I recently found out about My Immortal. If you don't know what that is, it's literally THE worst fanfiction ever written. The people are so OOC it's hilarious.
Anyway, the story I found today is called A Severus Snape Christmas Carol, and it's basically a parody of the Christmas Carol by Charles Dickens, but with Snape as Scrooge. I can't believe that no one's done this before, because it fits so well.
It's somewhat off-canon, but that doesn't really matter, since it's supposed to be a humor fic. Everyone's completely IC, except Ginny. But she's only a tiny bit off.
It's only one chapter, but it's a long chapter. I really recommend it, and you should probably save it to your favorites so you can read it around Christmastime. ^_^
You haven't clicked this link yet? Five points from Gryffindor. http://www.fictionalley.org/authors/qweasley10/ASSCC01a.html
