After the truly epic end to Supernatural's fifth season (with 'Swan Song', and Sam falling into the pit), it seemed difficult for the sixth season to go any bigger - but somehow, Supernatural managed it. Season six sees Sam return (of course - any fan knows that a Winchester never really dies), and the brothers face off against Eve and the original monsters, while a battle rages for control of Heaven.
For some fans, this is where the show started to take a bit of a downturn, but the ratings on IMDb are still impressively high - the worst episode of the season still manages to score a 7.7, while the best reaches 9.6. And that best episode is a fan-favorite from the entire series, as Supernatural steered into the comedy side of things and went a little bit meta.
Worst: Family Matters (8.1)
It's somewhat surprising that this episode doesn't score higher, given how much it moves the plot forward, with big reveals throughout. Of course - that may be the issue - it's all moving the story to the next place, and not a lot of humor or monster-mystery. 'Family Matters' reveals that Sam has no soul (for starters), thanks to Castiel checking him out, and that Samuel and the hunter-family are actually working for Crowley, who wants to take over Purgatory as well as Hell.
Best: The Man Who Knew Too Much (9.0)
The season finale usually does well in terms of ratings, and the season six finale is no exception. 'The Man Who Knew Too Much' brings everything to a head, as the wall in Sam's head comes down, and the Angels and Demons duke it out for control of Heaven. A lot of the episode takes place inside Sam's head as he deals with his memories, and Castiel ends up becoming wildly overpowered thanks to a ritual, and declaring himself the 'new God' by the end.
Worst: Two And A Half Men (8.1)
The second episode of the season, 'Two And A Half Men' starts with Sam and Dean still largely separate - Sam is working with Samuel, and Dean is with Lisa and Ben. His parental side is front and center this episode, too, as he and Sam find an abandoned baby while on a hunt. Overall, this episode doesn't really move the plot forward or stand out in terms of monster-of-the-week.
Best: Frontierland (9.0)
Everybody loves a little time-travel, and 'Frontierland' proves it. This episode sees the brothers convince Castiel to bring them back in time to the Wild Wild West in order to track down the original creator of the Colt, and find a way to stop Eve.
It has just the kind of enthusiasm and humor blended with lore that Supernatural fans love, so it's no wonder that it's one of the most popular episodes of the season.
Worst: Exile On Main Street (7.9)
It's surprising that this episode is one of the worst-rated of the season, as it is the premiere - and usually that means a solid reception! However, 'Exile On Main Street' fails to strike a chord with viewers, this time. The episode starts after months have passed since the season five finale, with Dean trying to live a 'normal' life with Lisa and Ben, until he learns that Sam is back, and he's been secretly hunting with Samuel. Perhaps this scores so low because it lacks the big, impactful, return that fans were hoping for - and confuses many, wondering if this is really Sam.
Best: Weekend At Bobbys (9.2)
Fan-favorites Bobby and Crowley are the focus of this episode - as Bobby attempts to force Crowley to return his soul. This episode also reveals Crowley's backstory, providing some extra humanity to the character, and some development of his relationship to the Winchesters, as they get the chance to destroy him (using his human bones) and do not take it - a surprising development, but a great one.
Worst: All Dogs Go To Heaven (7.9)
This episode gets dark, as Sam admits to how his lack of a soul is affecting him, while he and Dean uncover a pack of skinwalkers, turning into dogs as posing as family pets.
Evil Sam was a controversial figure this season, and hearing him admit to not really caring about Dean was a tough moment for fans to deal with - combine that with a monster of the week that makes family pets the bad guy, and it's no surprise that fans didn't love 'All Dogs Go To Heaven'.
Best: Appointment In Samarra (9.2)
The mid-season finale sees the return of Death, as Dean takes on his job for twenty-four hours, in return for Death's help in returning Sam's soul. In a series that deals with death and resurrection so often, 'Appointment In Samarra' is a fascinating look at destiny, and how the Winchester's tendency to mess with the natural order of life and death can change destiny. It also presents Death as a far more sympathetic character, as he helps Sam despite Dean not fulfilling a full day in his role.
Worst: Mannequin 3: The Reckoning (7.7)
This is one of the monster of the week episodes that simply does not have a happy ending - while the Winchesters manage to solve the case, it's far from a cause for celebration. 'Mannequin 3' sees Dean truly ending his relationship with Lisa, while Sam deals with a ghost that is tied not just to her remains, but to a kidney that she donated to her sister. It's a fascinating new twist on the ghost lore in the show, and ends only when the sister is accidentally killed - far from a win for the hunters.
Best: The French Mistake (9.6)
'The French Mistake' is one of the most popular episodes in the series, as Supernatural goes meta, and sees Sam and Dean Winchester moved to an alternate dimension to protect them from an angel... our dimension. They become Jensen Ackles and Jared Padalecki, actors on the set of a TV show - and seeing them act as their characters pretending to be their real selves is a brilliant move that the show pulls off perfectly. Funny, self-referential, and still plot focused? Of course this is a fan-favorite.