Starting off with one that I didn't rec last time because it wasn't up on Teaspoon at that time (though it had been posted elsewhere last year).
Story: The Wooded World of Worlds
Rating: All Ages
Word Count: 1366
Author's Summary: There exists a place where trees grow tall. [Narnia/DW Crossover]
Characters/Pairings: The Doctor (9th)
Recced because: One wouldn't think that Narnia is the kind of thing that could be crossed over with Doctor Who, or if they were, then the result would be silly. But this story captures them both where they intersect best -- in the deep and the mythical. Here we have the 9th Doctor, post-Time War, trying to lose himself in the peace and forgetfulness of the Wood Between the Worlds... and then he is visited by a Lion. This resonates so well; sad and beautiful, with a touch of hope.