If you don't mind WIPs, Where Are We Going from Here (http://archiveofourown.org/works/2734574/chapters/6127700) by River_of_Dreams sounds like the kind of thing you're looking for. Gabriel, Lucifer and Michael team up with TFW to fight Metatron. It has some background Sam/Lucifer, but so far it's mostly plot-focused.

Edited 2016-03-14 08:30 am (UTC)

Thank you! I'll check it out right away. :)

I don't know if this fits what you're looking for or not. It's a self-rec, so I apologize if you don't want those either.

I wrote it inspired by Castiel's remark to Dean: "Certain people, special people, can perceive my true visage. I thought you would be one of them. I was wrong." I figured that if he was expecting Dean to understand him when he was "talking" in his true form, then he had experience with charges that could actually do so. Thus, I created a character who not only could hear Castiel but was being used by the Angels to do their bidding, someone who'd been cursed to see the future and from a very young age had all of this responsibility thrust on her, someone who affected small changes to the Grand Scheme without anyone noticing to alter Destiny and give the Winchesters a fighting chance. All of it is canon and it explains a number of unanswered questions, including why John just walked away in Jericho and why the boys are stronger together than apart. It explores behind the scenes why Castiel did the things he did in season 4 and season 6.

even angels fall
http://archiveofourown.org/users/jenny_lynne/works?fandom_id=27 (http://archiveofourown.org/users/jenny_lynne/works?fandom_id=27)
John was always meant to break the First Seal. Sam was always meant to lead Azazel’s army, start the Apocalypse, and say “yes” in Denver. Dean was always meant to be the Sword of Michael.

The Hosts of Heaven and the Hordes of Hell had planned the Apocalypse down to the last detail. They were all sure Destiny and Fate could not be altered once set in motion.

Of course, no one took into account, the theory that if a New Orleans butterfly flutters her wings, a man in Jericho might walk out of his hotel room and change everything.

(A true-to-canon fanfic covering 25 years from pre-series through the end of season 6; explaining how Castiel and the Winchesters got from there to here and how an Angel's errand girl Saw the way to salvation and led the fall.)

Sounds interesting! I'll give it a go :)
And thanks for the rec ;)