Funnily enough I've got sam_castiel open in another tab right now, haven't been to the other place. Will go explore now.

And because one good turn deserves another; http://community.livejournal.com/spnstoryfinders

This place has a Sam/Castiel tag and I've ran across a few good ones there. You've probably read elise_509's fics right... if not you very much should... as soon as you possible can.