Where No Sheldon Has Gone Before....(Fan Fiction Recommendations)

[Idle Miscreant]

In response to a request from Cassius Moriarty (and who could ignore such a name?) we now have a Fan Fiction Recommendation Thread. Please deposit links to your favourite bits of verbiage here, along with, perhaps, a little spiel about what occurs within the story, or why you particularly favour it. Or you could just dump the link and scarper.
Like so;
"Partnership" by SpaceAnJL
http://archiveofourown.org/works/833431

General blether on the topic itself can also go here, naturally.