Turn of the Wheel by Hawk Moth is kickass futurefic that I can buy completely and utterly. No spoilers, just a sigh of pleasure: Simon. I'm all. about. Simon.
Let Be by Celli is a treat I saved myself for dessert. See, now that I've written my "Objects In Space" coda, I'm free to go read everyone else's. And of all that I've found, this one feels the most in character. Celli's got a great grasp of Simon and Kaylee, and the story just flows very naturally. I especially love the way she handles River.
Marital/Martial by Lizbet made me 12 kinds of happy. Yay! Wash and Zoe! I'm sorry, do you need more of a reason? Because that's about all I need, I mean it. Excellent Wash and Zoe, too. I'm all warm and fuzzy on the inside.
Fever Dreams by Nicole is a delicious little Simon/River "Objects in Space" coda.
In a Flash by Meegzi is a nifty keen look at a source of Jayne's animosity towards Simon that totally works for me.
Nor Ever Chaste by victoria p. is a spooky little Simon/River treat in the form of a coda to "Safe" that is not to be missed.
Therapy by Harriet Vane is another lovely little Kaylee/Simon missing scene from the pilot. The author needs a line edit--but if you overlook the occasional homophones and mispellings (which I know goes completely against the grain, trust me), she's got a great grasp of the characters voices and a nice subtle way with characterisation.
Day of Prayer, also by Harriet Vane, is a wonderful plot-driven little story that has the feel of an epsiode in terms of structure and pacing. Again, her mastery of her craft is rough--but her characterisations and dialogue are spot on.