I think that for me, Dean/Sam will always be the Nr. 1 pairing in this fandom. With their screwed up lives, it might actually fit.

But my main problem with Dean/Castiel was that I didn't understand the dynamics of the pairing, what I would prefer. Though it's true that Castiel is very protective of Dean, when Dean's in danger Castiel actually kicks ass. And I could get behind that ;)