I'm still deciding, but it's a close call! :) I am still buzzed and excited by how INCREDIBLE this episode was, at how much I enjoyed it....I actually just watched it a second time, just now, the first time I've ever seen an SN epp a second time right afterwards....I just had to see it again! I realize I may be the only one feeling this way, but oh well!
5x16 Spoilers:
It was just SO beautifully crafted, from the intense first scene and the gunshot followed by the bloody title card (first time I've loved that title card, lol), to Dean waking up in Heaven to "Knocking on Heaven's Door" (yay rock music too! And random fact, but apparently I'm related to one of the members of Guns 'n' Roses!), to the lovely fireworks memory (so happy to see Colin Ford again!), to all of the Dean/Sam angst and interaction, and the big mytharc moments. Plus just the surreal quality overall of the episode, and the fitting title "Dark Side of the Moon." Hell, even the "Then" segment at the beginning was epic, with the Death montage and amulet bits and music and such, I figured it would be a great epp from that, and then it was!
This episode, like 5x13, was the perfect mix of mytharc and Winchester storyline, there was just so much character development and interesting backstory here (which I can't wait to see others analyze!), plus exciting, game-changing mytharc developments! The huge difference between Sam's heaven memories and Dean's heaven memories, the fact that for instance neither had a heaven memory of their father (understandable, but still interesting, for Dean at least)--and yet another reason to hate John Winchester (along with the Mary stuff, jeesh!), the new insights about Dean's memories of his mother, and what his childhood was like, as well as what Sam's childhood was like, Dean's sudden desperate hope in God only to be crushed....so much there! I also found False!Mary's words to Dean intriguing, I wonder if Dean has especially felt like he might have been a burden to his mother since 5x13, when he learned she couldn't leave John because she was already pregnant with Dean? In any case, once again we see what a low opinion poor Dean has of himself! :(
Speaking of Mary and John, I was shocked about John/Mary, especially after our glimpses of them in 5x13....but I suppose that was the honeymoon phase, it's only natural for couples to fight sometimes, even if not to such extremes....now I really wonder what that fight was about! I loved Dean's reaction though, even at 4 years old, he was ever the peacemaker in the family, it would seem....Sam's line about Dean cleaning up their Dad's message was so heartbreaking too.
Also I'm really glad that they explained within the episode why Sam got into Heaven, despite his murder of an innocent woman in cold blood last season, it was bothering me since I learned about the episode, and I thought they had just forgotten about that....in all in fact I thought they did an excellent job at showing Heaven, which I was wary about when I first read they'd go there. I loved seeing Ash and Pamela and their memories, though I agree with Dean that it seems lonely, everyone with their personal heaven....given the way Ash mentioned the soulmate exception, I'm hoping that Dean and Sam count as soulmates (in a non-romantic sense), and that they would be able to share heaven, though this epp gives me some doubts....*sigh* I am angry at Sam, for his selfish heaven memories, and at Dean for throwing out the necklace (which I still can't believe, that's perhaps the most heartbreaking moment of all, of the series even!), but I can understand why each did what they did. The end of this epp was very depressing, and I really hope by the end they can reconcile somewhat....I'm hoping that Sam picked up the necklace out of the trashcan and that he will return it to Dean in some significant moment at the end of the season.
Speaking of returning the necklace, Cas also broke my heart utterly this episode....:( First his conversation via the TV, when he snapped at Dean so desperately, and noted that he could not return to Heaven (which has to suck for an angel), and then the way he looked so forlorn and crushed in the end, and even cursed at God....given how stoic he is, these outbursts just showed the depth of his inner turmoil. The "sonofabitch" also showed once again the extent to which Dean has rubbed off on him, to which he has been humanized a little. In some ways he was in an even more pathetic situation in the end, with everything he had always believed in utterly destroyed, his faith gone (Dean lost faith too, but he had only recently gotten it in the first place). I have to say, I was definitely not expecting the return of the amulet to go like that! I thought it was interesting the way that he affirmed Cas's harsh statement that it was "useless," though of course in any entirely different way than what Cas was thinking of..../sigh This episode certainly did tear my heart to shreds, and made me want to cry, but I still can't help loving it....
So much more to say about this episode....like Zachariah. I found it interesting to learn that he is not just pissed at the boys for not saying yes, but for petty personal reasons as well. I liked seeing him again in this episode, since I've always enjoyed his character, though I must say that I found his creepy sexual innuendo/advances on the false!Mary to be as disturbing as much of the gore on the show. I was thrown for a minute by this display, since angels aren't sexualized on the show, as we've seen before, but I suppose that Zach was just messing with their minds....ugh though! Also I wonder if Zach will return as a villain in season 6, a little like Gordon, given his little personal vendetta against the boys? We shall see....I also was a little surprised by the God revelation, I thought that there would be some other reason why he didn't interfere....maybe there still is, but he didn't share it with Joshua (who in himself was an interesting new addition to the angel garrison we've met--what was up with the gardening thing anyway?). And it was interesting that Zachariah seemed cowed by his threats about God's wrath--didn't he say before that God was dead? :s In any case, I am pretty disappointed in God.....though I was glad to hear confirmation at last of his role in the Soul Plane and Cas's resurrection, and in letting Sam into Heaven.
One small regret for me was that Pamela didn't mention the way Sam didn't follow her dying words, even in jest--it would have been a good opportunity for that. I mean, she slapped Dean, but Sam deserved a slap too....and I also am a little confused by Ash and Joshua's references to the boys being in Heaven before. Sam I can understand, but Dean? When has he ever died and not been bound by contract to Hell? (Aka the Mystery Spot deaths and of course the big one). I fear the writers might have forgotten about that and let in a little plot hole there....but overall, great episode!
Right now for me this episode is in a three-way-race with 5x04 and 5x13....