In which Dean turns out to be the archangel Michael (surprise!) and decides that they're doing this Apocalypse thing his way (i.e. not at all), the rest of Team Free Will (plus Gabriel) help out, and the Host, the demons, and various other characters are along for the ride (eg. fellow archangels, grumpy hunters, hapless prophets, etc). Alternate universe.

What if Castiel had taken a different vessel?

What it says on the tin. (Including Follow-ups to: Maybe one of these days you can let the light in, and One Of Those Things, and Mrs and Mr Pond..)

Discovering that you have some kind of angel-marriage, soulbond-thing to your nerdy angel friend kind of forces you to re-evaluate your relationship. In Dean's case, this involves freaking out and massive fail.

Apparently Supernatural was real, which was presumably why Gabriel was bleeding out onto Richard’s floor. (In which the actors of Supernatural find that reality is stranger and more disturbing than they previously believed, even counting Misha, and an injured archangel discovers that his universe is the subject of a TV show.)

Gabriel has a way out, if he can just get the gods on his side.

After the final Seal is broken, Dean discovers that he's actually Lucifer. He's not really sure how he feels about that.

Two hundred years ago the Winchesters stopped the apocalypse. Now, instead of getting into fights and running amok, eighteen year old Jim Kirk goes to live with his Auntie Sam and learns the family business. Four years later, an angel shows up.

Sam smiles, bright and luminous. "An angel's Grace isn't just power, Dean. It's a part of their soul." An AU 'verse that takes place after episode 5.22.

"Sorry, you have me confused with the other angel. You know, the one in the dirty trench coat who's in love with you." Dean and Castiel finally have that conversation.

Looking at the contemplative expression on Lucifer's face, Sam thinks that this has the potential to be either very bad, or completely awesome. Two humans and two archangels in the Cage.