The theory of silence and storms (Gabriel/Dean)
http://archiveofourown.org/works/1475716/chapters/3111718
Since the High Lord and his children took over Earth a century ago, winning the Cage has been the fast lane to fame and fortune for the champion. Defeat is not as pleasant: the loser is sold to the highest bidder. Of course Dean had to try. And to be honest, Dean thought that he would be the one on the podium after the last fight. Instead he is kneeling in the dirt, battered and bruised, the lords and ladies of America fighting to buy

Trinity verse (Dean/Gabriel/Cas) - I know you didn't want Cas but it's a triad relationship and really long and good :-)
http://archiveofourown.org/series/28444
This author writes lots of Dean/Gabriel

Stand a little rain (Dean/Gabriel)
http://archiveofourown.org/works/1322947/chapters/2753239
What if everything depended on a single, simple choice? Right after Sam left for Stanford and John took off for hunts unknown, Dean met up with a man in the middle of the afternoon over lunch - and they elected to spend the rest of the day (and night) together. Should have been a simple one night stand for Dean and Gabriel - except Gabriel forgot one thing in the heat of the moment - there are times when angels can impregnate a human, regardless of their gender. When he realized the possibility - he went to find Dean. When he found him, Gabriel decided that the best thing to do for everyone is to stop the whole Apocalypse cold. Unfortunately, he didn't count on Michael having an issue with his little brother playing house with his true vessel and their half-angelic daughter, Sara.

If you don't mind a crossover- Dean/Jax (sons of anarchy)
Biker verse http://archiveofourown.org/series/22126