Few shows have ever lasted as long as incredible post-Kripke era episodes and stories, the show continued drawing in and impressing fans.
Every new season of the show offered something for fans, with only a couple of the fifteen being truly bad. Even if the finale left a lot to be desired, the show's run provided fans with some genuinely excellent seasons of television.
Updated on July 31st, 2021 by Rhys McGinley: After fifteen years, Supernatural finally called it quits, closing the book on the story of the Winchester brothers. In the end, the show's finale ended up infuriating many fans, and ittedly, there was a lot that went wrong. Nevertheless, for a show that ran for fifteen years with such an expecting fanbase, the show continued to provide the goods season after season. There were apparent low-points where seasons just did not work, but out of the fifteen, there were multiple seasons that were truly amazing and only two or three could be considered flat-out bad.
Season 7 (2011–2012)
● No. of episodes: 23
This season is the worst of them. Castiel is gone for most of it, which alienated many fans at the time who had come to love him. They realized their mistake and brought him back, of course.
The Leviathans have the potential to be interesting, but it's another case of trying to top what they already did the best of. There is then that Bobby randomly and unnecessarily died, and lack of threat presented by the Leviathan, all of which drag this season down.
Season 12 (2016–2017)
● No. of episodes: 23
This season just started to get ridiculous, and it didn't do the show any favors. The biggest issue with this season is how painfully forgettable it is; it is hard to think up all of the significant events of this season off the top of the head.
There's just nothing that can have impacts like Lucifer, or Death, or a brief, vague introduction to God, and this is where it seemed like the fans were right to say that Supernatural was starting to beat a dead horse. This season led to better things, such as Jack, but was overall painfully below average.
Season 9 (2013–2014)
● No. of episodes: 23
Season 9 dealt with the fall of the angels, which was a pretty cool concept, but it just wasn't as good as the earlier ones. The season never reached the heights of season 8's finale.
The angels on Earth were so initially fascinating, but it quickly becomes clear there is one glaring problem, the angels themselves were not interesting. It does have an iconic season finale, but with a villain like Metatron and a dragging angel story, as well as one of the more lackluster Dean/Sam disagreements, the season is not great, even if it did give birth to a vicious Mark of Cain wielding Dean.
Season 6 (2010–2011)
● No. of episodes: 22
Season 6 is the aftermath of where the series arguably should have ended, and it just feels tacked on. Sam is, once again, brought back from the dead, and it makes the audience feel as if death has no consequence for the brothers anymore.
Soulless Sam is an intriguing concept, but even then, it doesn't make sense why Castiel hid that he brought a villainous Sam back from Hell. Cas going dark at the very end just seemed wildly unlike him (especially since he's so quick to apologize when he realizes he's dying). It was not a fantastic start for the post-Kripke era of the show. Although, it did give fans "The French Mistake." Just look at the whole Eve arc as an indicator of the failed potential of the season as a whole.
Season 14 (2018–2019)
● No. of episodes: 20
Season 14 is a wild season, cut in two halves, first focusing on Michael as the villain before moving on to more of a focus on Jack and Chuck.
There are two significant issues with the season. For one, it can be incredibly slow, and the first half is not as good as the second. For two, it spends a lot of time laying the groundwork for the final season, which is understandable but does not help this season as a whole. It is incredibly emotional, though, with "Lebanon" being a shining moment in Supernatural history, as well as showing the true family values between the four of Team Free Will. It also has one of the show's best season finales and cliffhangers.
Season 15 (2019–2020)
● No. of episodes: 20
Going into its fifteenth and final year, a lot was riding on the Winchester brother's last ride, and it is likely the finale will be debated by the ionate fandom for years to come.
The season starts well, continuing from season 14's outstanding cliffhanger, but does slow down as far as the grand plot goes. Chuck spends more time plotting in the early days of the season rather than doing anything. Things do ramp up, though, and fans get treated to some wonderfully emotional Winchester brothers content, a heartbreaking goodbye from Castiel, and apocalyptic stakes. The finale could have been better. More characters really should have been there. It was emotional, tear-inducing, and chock full of fan service. It was not for everyone and will not be to new fan's liking in the future, but the final season was far from the worst season of the show.
Season 13 (2017–2018)
● No. of episodes: 23
After a wildly disappointing twelfth season, season 13 managed to up the quality and gave fans some great stuff. This was the kind of season that proved the show's longevity with its experimentation and changing things up.
While Jack Kline was divisive for some fans, he was beloved by many throughout his time in Supernatural. The show, of course, missed Crowley, and there was a good bit of filler. It also is not the best Sam and Dean season in of arcs. However, with the alternate world, the sheer level of improvement from twelve, and the consistency, as well as Jack shining, it is a good season. Seasons 13 through 15 are all interchangeable depending on personal taste, though.
Season 1 (2005–2006)
● No. of episodes: 22
Season 1 was a solid introduction to the show as a whole. Viewers met the two brothers, Sam and Dean, and get given insight into their horrifically tragic past.
The format was much more of a horror show than the later seasons, and even now, watching it gives off serious nostalgia vibes. The show was just finding its feet, but despite that and despite episodes like "Bugs," season 1 managed to be something really great and will always hold a special place in the hearts of fans.
Season 10 (2014–2015)
● No. of episodes: 23
This season mainly revolves around Dean and coping with the Mark of Cain, which gives fans one of the best and most complex seasons of Dean Winchester in the show, a joy to watch.
The iconic Deanmon is far too short-lived, which did not set the season up well. However, it did brilliantly bring in Rowena MacLeod, tease fans with Chuck, and had some awesome episodes like "Fan Fiction," "Book Of The Damned," The Executioner's Song," and "The Prisoner." Sam and Dean's relationship is also fantastic consistently through the season, giving the show some normalcy through the chaos.
Season 3 (2007–2008)
● No. of episodes: 16
Season 3 was, like season 5, a place where the show could have ended and been good. The season was spent racing to break Dean's deal with a demon that would land him in Hell in a year.
Dean being ripped apart by a Hellhound is a lasting, horrifying image, as is that of him in the pit while Sam cradled his broken body. Like many shows of the time, the season fell victim to the infamous writers strike but still managed to be a terrific season of Supernatural, one of the very best.
