Stranger Than Fiction (http://nyxocity.livejournal.com/187348.html)
Summary: Set immediately post-The Monster at the End of This Book. Dean can't stop wondering why people would write gay porn about him and Sam. Research takes him to interesting places; re-reading novels for subtext, visiting message boards, and a really freaky place called LiveJournal. What he discovers is a sick fascination with fanfiction, more about gay sex than he ever wanted to know, and an even deeper obsession with understanding why people write this stuff. Meanwhile, they're hunting a mysterious monster that takes the form of a person's truest love to kill them slowly, the lines between fanfiction and reality are starting to break down, and they still have to stop Lilith and save the world.

Hi I hope you don't mind a little self pimping, but I wrote a little something that might just fit the bill.
The Rack. (http://sasha-dragon.livejournal.com/33218.html)
Summary: Working on Supernatural can be hazardous for your health, both mental and physical. In other words take three bored actors, one very special guest star, add a dash of fan fiction and stand well back.

Edited 2012-06-04 10:33 pm (UTC)

check out the Fandom, Fanfic & Fans (Oh My!) (http://j2-recs.livejournal.com/tag/discover%20fanfic) posting at j2_recs

Manufacture a Miracle (http://tebtosca.livejournal.com/41819.html) by tebtosca:
Jensen and Jared are fic writers who take their rivalry very seriously--well, as seriously as a show about a zombie apocalypse can get. But when they imprint-at-first-sight while at a fandom convention, Jensen has to battle horny TV stars, physical exhaustion, and the loss of his favorite shoe to convince his brain what his body already knows--that Jared is his soulmate.

Fourth Wall (http://libraryofsol.livejournal.com/106018.html) by entangled_now
This is a series that explores how the in-show Supernatural fandom affects the boys, so it's kind of slash, kind of crack, and all kinds of funny. It's also a decent alternate telling of Season 5, apocalypse and all. Start with Browser History and read on through. The tag doesn't work, so you have to browse through her dean/castiel listing.

Supanachuru (http://community.livejournal.com/dejuramortis/25406.html) by seraphim-grace.
"The second gospel has appeared to the Winchesters, via bootleg from Chuck, an Anime" A wonderful melding of anime, show and real-life.