I love fics where Dean is protective. I want Dean being protective over Cas, and when Cas gets hurt he just looses it. Either Cas being surprised or used it works for me. Or Sam isn't surprised because Dean is always super protective over Cas but Cas is confused or shocked.
It can be a familial relationship, best friends, or a relationship, any work. I'm not a huge fan of AU's, I like to stick to the Supernatural world.
Thanks!