"Survival of the Fittest"
At the end of season seven, Dean finds himself trapped in purgatory. Yikes!
"Death's Door"
Bobby (Jim Beaver), the boys' beloved father figure, dies, leaving them truly on their own.
"Time After Time After Time"
Dean travels to the '40s, looks hot in a fedora.
"The Man Who Would Be King"
Cas (Misha Collins) goes to the dark side! Turns out, our favorite angel had teamed with Crowley (Mark A. Sheppard) to harvest souls all season long in order to get to purgatory. While he thought he was doing what was necessary, Cas clearly knew he was wrong.
"Frontierland"
Giddyap, cowboys! In order to meet Samuel Colt, the boys travel back to the wild, wild West.
"The French Mistake"
Talk about meta! In this episode, Sam and Dean are thrown for a loop when they enter an alternate reality where they are actors named Jared and Jensen on a show called Supernatural. Genevieve Padalecki, Jared's real-life wife and former Supernatural star (demon Ruby), returns to play Jared's Jensen-hating wife.
"Live Free or Twi-hard"
In this satire of young girls' obsession with Twilight, Dean gets turned into a vampire...as a soulless Sam watches and does nothing to stop it.
"Exile on Main St."
Sam's back, but he left something behind in hell: His soul. Also returning with him is grandfather Samuel (Mitch Pileggi), who turns out to be a real douche.
"Swan Song"
In what was originally intended by creator Eric Kripke to be the series finale, Sam says "yes" to Lucifer (Mark Pellegrino) and plans sacrifice himself to send him back to hell. The plan works with Sam leaving a devastated and broken Dean with nowhere to go but Lisa's (Cindy Sampson) doorstep.
"Hammer of the Gods"
Recurring villain the Trickster turns out to be the angel Gabriel (Richard Speight Jr.), who has been hiding from Lucifer and Michael.
"Abandon All Hope"
In a failed attempt to take down Lucifer, Sam and Dean pay a steep price: The lives of their friends Ellen (Samantha Ferris) and Jo (Alona Tal). Their death scene is one of the series' most heartbreaking moments ever.
"Changing Channels"
In one of the series' funniest episodes, the Trickster traps the boys in different TV shows, including a buddy comedy and a medical drama. (Hi, Dr. Sexy M.D.!). Oh, and a herpes medication commercial.
"Lucifer Rising"
Siding with Ruby over Dean, Sam inadvertenely opens the gate to hell and unleashes Lucifer from his cage. Oops?
"The Rapture"
Dean finally uncovers the truth about Sam's demon-blood-drinking secret.
"The Rapture"
Viewers met Jimmy, Castiel's human vessel, in this episode, which also gave us insight into the life and family Jimmy left behind when he said "yes" to being a vessel.
"Jump the Shark"
There's a third brother! Yes, John fathered another boy, Adam (Jake Abel). Too bad that boy was killed by revenge-seeking Ghouls, who used Adam's skin-suit to lure Sam and Dean. Bummer.
"In The Beginning"
When Dean is transported back to the '70s, before his parents were even married, we learn that it was the brothers' mother, Mary, who was a hunter, not John.
"All Hell Breaks Loose, Part Two"
Desperate and distraught after Sam's death, Dean follows in his father's footsteps and makes a deal with a demon to bring Sam back. The catch? He only gets one year to live. It's also revealed that the Yellow-Eyed Demon Azazel fed his blood to Sam as a baby, which is the reason Sam has the ability to see things before they happen.
"Heart"
For the first time since Jess's death, Sam feels a connection with Madison (Emmanuelle Vaugier) and sleeps with her, only to find out she is the werewolf they have been hunting. Reluctantly, Sam kills her when she asks him to.
"Hunted"
"Before Dad died he, he told me something—something about you. He said that he wanted me to watch out for you, to take care of you…He said that I had to save you. He just said that I had to save you, that nothing else mattered; and that if I couldn't, I'd...That I'd have to kill you. He said that I might have to kill you, Sammy." Boom.
"In My Time of Dying"
To save Dean's life, John (Jeffrey Dean Morgan) makes a deal with a demon, trading his life for his son's. Sob!
"Devil's Trap"
Fans were left to sweat it out over the fate of the three Winchester men when the beloved Impala was hit by a truck in the season-one finale's final moment.