http://trueshellz.livejournal.com/45787.html - J2, Office AU, starts PG-13 but eventually moves up to NC-17, totally my kind of humor.

http://sparseparsley.livejournal.com/8666.html - Castiel/Dean, AU, NC-17, one of my favorite Cas/Dean fics

http://tuesdayfic.livejournal.com/20203.html - Cas/Dean, NC-17, another favorite, I recommend watching the video that inspired it.

http://tigbit.livejournal.com/81373.html - J2, AU, NC-17, super long and worth every word.

there's more, but I forgot to bookmark, sorry :(

http://tuesdayfic.livejournal.com/20203.html I second this so hard. It's a master-piece.

Sam Winchester and the Terrible, Horrible, No Good, Very Bad Day. by leonidaslion

http://community.livejournal.com/leonidasden/29762.html

Whammied! by_mournthewicked

http://users.livejournal.com/_mournthewicked/244611.html

One more that I think was funny:

Cooler by lemmealone

http://community.livejournal.com/paynodebts/4175.html

This is guaranteed to make you LOL. It's really pre-slash Dean/Cas, but seriously, so hilarious. Here's the link to the crack_van rec with links to all three stories.

http://community.livejournal.com/crack_van/4005165.html

I *love* that series! Cas swearing, with such emphasis, and doing it wrong never fails to make me bust out laughing when I read it. :-)

you guys are to awesome for words. my day shall be full of laughter and rainbows, and what looks like it might be some seriously epic wincest and angel porn.

so thank you for that.

wincest cookies, all around.

Neon Showman (http://atimi.livejournal.com/10597.html) It's J2 from Chad's POV and I don't know what your opinion of Chad really is, but dude. Dude. I nearly busted a couple of veins from trying not to laugh too hard. Chad is hilarious in this!

Emo (http://boonies.livejournal.com/180907.html) Implied wincest, with Sam and Dean being stuck with a five-year-old orphan. It's really, really, really funny and extremely adorable.

Anti-Kink Series (http://www.livejournal.com/tools/memories.bml?user=ash_carpenter&keyword=Anti-kink&filter=all) A series of wincest fics featuring Sam and Dean and their failed attemps to introduce some kinks in their sex-life. The voyeurism and car!sex ones are the funniest things I've ever read!

Cutting Humor (http://www.fanfiction.net/s/2912515/1/bCutting_b_bHumor_b) Gen with Sam and Dean trying to take care of each other two separate times when the other is injured. Very funny and the second chapter is pure brilliance!

Here's a link to a J3 fic which I absolutely loved!(there's no actual threesome happening, it's just about Jared and JDM competing for Jensen)
'Two's A Company, Three's A Headache Of Epic Proportions'
http://saone77.livejournal.com/153919.html#cutid1

If you'll like it, check out other fics by saone77, they'll all similar in style and hilarious. My favourite:
'This Could Get Messy' and the whole Killer Romance
http://saone77.livejournal.com/148551.html#cutid1

and 'It's the Most Wonderful Time Of the Year'
http://saone77.livejournal.com/152124.html#cutid1

Hey, can I get the link to Start Reading Shakespear and I'm Out of Here? please and thanks!

http://www.fanfiction.net/s/8374517/1/Fifty-Shades-of-Red
http://www.fanfiction.net/s/9057725/1/La-Traviata-AU
http://www.fanfiction.net/s/9200933/1/Misha-Collins-vs-Prenda-Law-Firm