Every time it is very difficult to choose. I'll be brief: I find that the final of @calluna is a cut above all others for the quality of writing, but this time I would like to give my vote to @agmoore because she did something that no one had yet done in the FtS: she used the story as a pretext to tell us an anecdote of her childhood and to give us many interesting information about entomology and even... robotics!
Plus, I already like those little and very organized cockroaches!