I'm pretty sure everyone on my flist who watches the show is properly caught up, but for formality's sake I'll make a spoiler cut.
Ok, the season was fantastic. There were some parts that I didn't like, mostly just the portrayal of angels. They were far too human. Angels aren't slaves to emotion like we are, and they're certainly not as limited as they were portrayed in the show, and as
kojonoyuri pointed out to me there should be no reason for angels to fear demons like they seemed to in a few of the episodes. I also thought the storyline of the angel Anna becoming human was stupid. Just the idea that an angel could do that I find silly, but especially that she did so by "ripping out her grace" and that grace is a physical entity which can be bottled up and carried around.
BUT the season won in so many ways, most especially (in my opinion) with Ruby. They've worked so hard over the past two seasons to show us that she's on our side and did so well with it that I was absolutely flabbergasted when it turned out that all along she was actually working to free Lucifer. I'm impressed with Ruby as a character for executing her plan so flawlessly (though another problem I had with the season was the way that Ruby and most of the other demons were much smarter and in control than the angels) and with the writers for giving such a genuine twist, one of the best twists I've ever seen, especially in a TV show. I can't believe how crushed I was to see that she had been deceiving Sammy all along, and that everything he'd been working for and sacrificing his humanity for ended up causing what he was trying to prevent.
Which leads me to poor Sammy. God, this season was rough on the guy. First he's so torn apart about Dean being in Hell which leads him to desperation and depression to the point where he doesn't even care if he lives or dies. Then Ruby comes along with a plan to "help" him and he believes her because he trusts her. She works with him to improve his psychic powers but he does so by drinking demon blood and sacrificing more and more of his humanity each time just trying to be strong enough to stop Lilith. Then he meets the angels, whom he always hoped really did exist, and they're disappointed in him and see him as a monster. Still he keeps working with Ruby to become strong enough to kill Lilith and little does he know that all this time Ruby's been working against him and killing Lilith actually breaks the final seal and releases Lucifer.
Favorite episode of the season? Easily episode 13 "After School Special". First off, best casting of younger Dean and Sam the show has ever had:
especially Dean. When the scene first started I couldn't figure out why Jensen looked kind of different until little Sammy got out of the car and I realized it was a flashback. The story for the episode was great; I loved seeing Sammy trying to defend his friend in the flashbacks, and the friendship that could have been, and the life that could have been saved, if only they could have stayed longer. It was wonderfully tragic. I loved that the bully who picked on Sammy's friend turned out to be bullied himself and that Sammy fighting him on behalf of his friend only added to the kid's torment. I thought it was a great "two sides to every story" kind of deal, and learning the unforeseen consequences of your actions.
Plus, as a future teacher, I loved that the teacher made such an impact on Sammy that he wanted to see him again and thank him. I hope I can make an impression like that on a student some day.
Now I need to hunt down season 5 online because the full episodes aren't on cwtv.com and I don't want to have to wait for the DVDs to come out.