Crossovers
House/Firefly
A Gentleman (And A Thief) by
leiascullyAwesomely in character and adorable story in which Mal shows up at the Princeton-Plainsboro free clinic, and Cuddy takes care of him.
*
Supernatural/Harry Potter
Old Country by
astolatA really fun crossover in which Dean inherits a wizarding estate and wacky hijinx ensue. The story contains Wincest, but the sex has a coercive element I found exceptionally squicky; since it's also completely unimportant to the plot, you can easily skip it, and the rest of the story is worth doing that. Dean + Hufflepuffs + Goblins = awesome.
*
Supernatural/Friday Night Lights
When All You Have Left Is by Molly
Lovely and heartbreaking. It's the end of the world, but Tyra has Sam and Dean Winchester looking out for her. (Tyra/Sam, Tyra/Dean)
*
Supernatural/Sandman
Harvester of Eyes by
gwendolyngraceFantastic. John is hunting the Corinthian and Sam and Dean slip through a Soft Place into the Dreaming. Excellent use of the Sandman story and characters, and a tight, suspenseful, moving story.
***