Supernatural is essentially about two brothers that travel back and forth across the country, seraching out things that go bump in the night, and bumping them right back. Okay, so I more or less stole that from Hellboy, but it's no less apt for it, just replace bump with kill and you'll get the idea. For the most part I feel that Supernatural is at it's best when the boys are tracking down random baddies and putting the hurt on them. The overarching storyline can still be fun, but it's not where the show shines. In the current season, we see that Sam and Dean have both worked to kick off the Apocalypse by releasing Satan from his prison, now all that's left is for Satan to possess his vessel, and the archangel Michael to possess his, and then they duke it out. The twist here is that Dean is Michael's vessel, and Sam is Satan's. Naturally the boys aren't too keen on letting a couple of angels possess them, then duke it out, leaving the winner in a persistent vegetative state, and the loser just dead. To that end, they try to track down the magical Colt handgun which can supposedly kill anything, hopefully even an angel.
The one thing that I really like about the Apocalypse episodes is that they include the rogue angel Castiel, who has come around to the brothers' notion that neither the good guys or the bad guys should win this. However instead of looking for the Colt, Castiel has decided to find God, who's been on some sort of sabbatical for a really long time.
The most recent episode found the Winchester's on the trail of a recurring character, the Trickster, a demigod like creature that is able to warp reality in just about any way he sees fit. They set about trying to track him down, although instead of trying to kill him this time, they try to enlist his aid in averting the Apocalypse. The twist comes in that he's not exactly against the idea of the Apocalypse, trapping Sam & Dean in a series of TV shows, in order to teach them the lesson that they should "play their roles" and let Michael and Lucifer possess them and duke it out. There's a great deal of humor here, with them becoming doctor's on a Gray's Anatomy type show, a sitcom, a Japanese game show, CSI, a genital herpes commercial, and more. Eventually Castiel shows up, looking bloodied and bruised, saying that the Trickster is more powerful than he should be, which eventually leads to the revelation that he's not a Trickster, but another Archangel, Gabriel this time, apparently he couldn't stand his brothers and sisters fighting constantly, and decided to run away and just amuse himself on Earth until the world ends. Eventually they manage to make their way out of the TV world, and tell Gabriel that he needs to stop being a coward and do something about his problems. Not really what I was expecting to take away from the episode, but it gave me a lot to think about, oddly.