I can't think of a time an episode of supernatural has thrilled me more from start to finish.
The big opener was great, and i'm so glad they surprised me by not doing the whole 'X hours earlier' routine, but instead moved the story on to something completely different.
The whole whore of babylon thing was a nice way for them to still stay on track with the apocalypse story, while still having some of the greatest fight scenes supernatural has seen (sam and his knife!).
They topped it all off with the amazing scene between dean and the mother of his child, setting up for what can only be dean finally saying yes to michael, albiet with a few terms of his own.
I really can't wait to see how they tie it allup in these last few episodes.