Supernatural
Dean & Sam: I loved the fake out we get when Dean says he's tired, and Sam's expression which is part "I should have known" and part dismay over just how broken Dean is. And the fact that it uses Sam's belief in Dean's weakness to trick Sam, which is the only reason he wouldn't be able to see that trap coming. Don't worry, Sam. Dean does still have the capacity to freak out over this, and he's going to freak out like he's never freaked before.
Dean's side is pretty easy to see, given that he saw Sam lose control like an addict right in front of him. The fact that he immediately killed the demon with the knife afterward destroying the notion that he did it for the sole purpose of getting the power to exorcise them.
I am now seriously thinking we might have a rift over the summer hiatus. D:
I'm sure it would be solved in the first few Season 5 episodes, since anything else would be altering the format of the show too much, but I really want a finale more like AHBL. One where there's a host of problems but you're left with the feeling that Sam and Dean will be able to solve them. Together, hint hint. Come on, Kripke! Alternate your finales between despair and hope (except your series finale better end hopeful. I'd let this finale be all black, black despair if I knew the endpoint would be good for the boys).
Castiel: Well, the fact that the vessel's still in there puts a damper on the slash. The fact that Castiel found it necessary to point out forcefully that he didn't serve Dean is awesome though, and fanfiction writers have had to work around harder problems.
Nice to see you can beat some demons, as long as you're in a little girl and not Jimmy. Or I can be nice and put it down to Alistair being such a high-level demon and/or your sympathizing with humans affected your power.
Not sure what I'm supposed to think of you warning Jimmy about the horrible life he will lead, when the alternative is to give that horrible life to his little girl. I believe the possession was willing the first time, but there was definitely coercion here.
Anna: ANNA! You were barely there but I loved your scene. Giving us the knowledge that angels can sense something's up with Sam, and presumably also let Sam and Dean know that demons would be interested in not only what Jimmy might know, but how he was able to be a vessel in the first place. I loved the way you just popped up and freaked out the boys. And Dean's inappropriate remarks.
Vessels: I find it interesting that the ability to be a vessel for angels is genetic. Does this make sense of the shepherds at Jesus's birth seeing a host of angels (assuming that happened in SPN canon)? That they all were of that bloodline?
And why do they need vessels? Anna isn't possessing anyone. Is it sacrilege to make a body for yourself in the shape of a human? Is that why the angel still needs the vessel's soul still in there? I am very confused over this body possessing thing.
Also, the timeline does not make sense between Castiel raising Dean out of Hell, trying to speak to him and then taking a vessel. There was enough time to get Jimmy prescribed pills, so at least a week, and it does not make sense. Arrrgggghhhh.
Jimmy: I thought that besides being possessed we were going to find out the Neighbor!Guy was seeing your wife, based on her level of discomfort with him coming over. He's dead now, so I guess it doesn't really matter. Chained to a comet? Poor you.
Also: I'm disappointed we didn't get to see SPN's take on the Rapture, despite the episode name. I'm sure it would have been hilarious interesting.