Different As It's Always Been (http://runedgirl.livejournal.com/66274.html) by runedgirl: "On a cold November day in 2015, the demons finally gave up on Earth and went back to hell. The angels left a day later. Sam woke up in the bunker the morning after everything changed feeling exactly the same. It took four years, three weddings, two guinea pigs, and Dean nearly dying for Sam to realize that nothing was the same after all. Especially his feelings for his brother."

After the End (http://archiveofourown.org/works/1727609/chapters/3683639) by amypond45: "Dean disappeared the night of his death. Sam's alone in the bunker, researching ways to bring Dean back, when a certain handsome devil shows up."

Crossed Wires (http://archiveofourown.org/works/5454641) by rivkat

And these two are pre-bunker season 8, but definitely worth checking out:

Becomes A Monster (http://runedgirl.livejournal.com/63320.html) by runedgirl

Brothers In Arms (http://archiveofourown.org/works/984035/chapters/1938744) by travellerintime

First time, long and plotty, Season 8, complete, but pre- bunker:
Sam's Confession (http://archiveofourown.org/works/1007180/chapters/1997078)
The fights and bitterness between them have finally driven Sam past the breaking point, forcing him to make a choice that he might not return from. He leaves Dean everything including a heartbreaking confession on the laptop that not only reveals some things Dean didn’t know of that lost year but also a startling secret that Sam’s kept for thirteen years…a secret that forces Dean to examine a lot as he rushes to not only save Sam but to face how much he’s willing to change. *Angsty/depressed/dark thoughts/suicidal!Sam & Upset/ angry/concerned!Dean* Set in S8 between Torn and Frayed and LARP & The Real Girl. (Dean/Sam) 1st time Wincest.
19660 words