zara_zee's Gladiator, A Love Story
riyku's Fair Winds and Following Seas
clefink's Muse FM
cherie_morte's Shipwreck Between Your Ribs
But as I'm sure everyone was going to read those anyway given that they are all such awesome BB veterans, so how about one possibly less well known
shadow_cat's Untitled Superheroes - that is a pretty damn good superhero romp and I enjoyed it a lot.
Non BB recs - El Dorado by nigeltide. I'm in the middle of this one at the moment and it is really very good. It's an SPN western AU and creates a wonderful sense of the period. Sam and Dean are apparently unrelated and become acquainted early in the fic, and the story so far is a slow burn, watching their relationship develop from Dean's POV. I'm waiting to see if it turns out they are brothers, though so far it looks like it could go either way. Well worth a read!
And a late addition from summergen Children of the Ressurrection
It's a perfectly lovely outsider POV set in season 8, and the outsiders are so well drawn you are pulled into their story quite happily. Winchesters are a bonus!