I knew they were going to draw that parallel between Dean and Cain. I honestly groaned when they did. Although I liked what Dean said about family (though Cain had a point when he said "where is you brother now"). And I admit I did cringe a little when Cain gave him the mark. I know he wants to use it to kill Abbadon, but I hope that is all he will use it for and not something else.
Always like Dean and Crowley working together.
As for Sam and Cas...that scene about the PB&J... I thought Cas had eaten food before as a human. Wasn't it in My Bloody Valentine when he was going crazy eating all the burgers? Or does that not count because he was affected by Famine like almost everyone else?
The fact that Sam wanted Cas to keep going with taking out the grace, and what he said.... It was heartbreaking. I did like what Cas said to him about Dean though or rather about the two of them. And about Sam himself. Did anyone think that Cas healing him after the grace was out was too easy? Though I don't know how else Sam could have been healed...