One of the most underrated paranormal fantasy series of the 2010s is NBC's Grimm. The series follows a Portland detective named Nick Burkhardt who learns he is a Grimm, a person who has the ability to see the true forms of paranormal beings known as Wesen. Nick must learn to balance this legacy of Grimm's and keep the peace between the human world and the Wesen world.

Grimm is an incredibly ambitious series that takes the best elements of a fantasy drama and monster of the week series with a hard-hitting procedural detective series. Grimm had an incredibly ambitious run on television and was unafraid to push the boundaries with every season. Some of these seasons were better than others and each represented an important part of Grimm's journey into becoming a cult classic among both fantasy and detective TV series.

6 Season 1 Was a Foundational but Imperfect Season

Season 1 has a 55% Critical Score and a 81% Audience Score on Rotten Tomatoes

Season 1 of Grimm set the stage for the series. The first season of Grimm had the challenging task of introducing a complex world rife with different species of Wesen that was hiding underneath the surface of humanity. This hidden world being revealed to the viewer fits in seamlessly with Nick's journey of discovery, creating a symbiotic experience that sets the tone for the season. The highest-rated episode of Grimm Season 1 is the 22nd and finale episode, "Woman in Black." This high-octane season finale benefits from the careful plotting of the worldbuilding and sets the stage for a complex plotline to be explored in Season 2 involving many aspects of the story, including Juliette and her exposure to the Wesen word.

The first season of Grimm had trouble reaching its full creative potential due to the severe amount of worldbuilding that was needed to build the series. While the first season laid some important foundation for exploring Wesen history and Culture, it did neglect the characters themselves by not exploring their nuances. Season 1 of Grimm did its job, but it pales in comparison to the nuanced later seasons of Grimm.

5 Season 6 Stumbled Too Far Away From the Original Grimm

Season 6 has an 83% Critical Score and an 88% Audience Score on Rotten Tomatoes

Season 6 felt like a wholly different series from the early days of Grimm. The shortened season attempted to blend in a bold finale storyline with the procedural episodes that had a 'monster of the week' story style. The result of this move was a disjointed season that felt like a fever dream compared to the exciting but familiar feeling of previous seasons. The highest-rated episode of Season 6 of Grimm is Episode 12, "Zerstörer Shrugged." The episode precedes the series finale of Grimm and sets the stage for the biggest fight Nick and his friends have ever faced. "Zerstörer Shrugged" sets up the finale plotline incredibly well and blends emotion with action to create a deeply impactful episode.

The antics of Season 6 highlighted the stark changes that have been made to Grimm over the course of six seasons. This was divisive for fans who were displeased by the strong changes from the earlier seasons of Grimm, such as the departure of Juliette and the addition of Eve. The final episodes did tie the newly introduced Season 6 finale storyline elements of the story together and gave a fair sendoff to Grimm in the series finale episode.

4 Season 5 Took Creative Risks With Storylines

Season 5 has a 100% Critical Score and a 91% Audience Score on Rotten Tomatoes

Season 5 of Grimm introduced one of the most intense storylines of the series. Season 5 introduced a secret society whose political machinations posed a great threat to Nick, as well as his family and friends. The Black Claw storyline was a shock to the system for Grimm and continued the series trend of building on the rich lore that had been laid as a foundation by earlier seasons. The highest-rated episode of Grimm season 5 is Episode 22, "Beginning of the End: Part 2". This is the final episode of Grimm Season 5, and it pulls no punches when it comes to the action. The Black Claw storyline is one of the most dangerous threats the team has ever faced, and it challenges them more than any enemy has challenged them before.

Season 5 of Grimm set challenges for the characters that forced them into tense situations and pushed them to the emotional brink. These emotional scenarios encouraged character development and benefited the story. However, the new ground for Grimm did have an air of unfamiliarity that turned off some fans as they felt the series was losing its roots.

3 Season 2 Foreshadowed Great Things For Grimm

Season 2 has a 100% Critical Score and a 91% Audience Score on Rotten Tomatoes

Season 2 of Grimm built on the lore established in the prior season to continue expanding the world of Grimms and Wesen. Season 2 introduced scarier Wesen with more depraved and complex behaviors that Nick and his friends must combat. Season 2 continued to expand the world of Grimm by distributing details about new Wesen and Grimm lore into the procedural style episodes that stood on their own while contributing to worldbuilding. The highest-rated episode of Grimm Season 2, Episode 12, "Season of the Hexenbeist." "Season of the Hexenbeist" has some of the most intense plot moments of the entire season. Several plotlines reach their climax, such as Juliette's magically induced affair, and leave the team scrambling to recover from the shocking moments while still being on guard against their enemies.

The second season of Grimm balanced the procedural elements with a shocking overarching plotline surrounding Juliette. Juliette had been cursed by Adalind, who concocted a calculating plot to target Nick. Juliette's curse and her coming closer to uncovering Nick's world of Wesen created tension in Nick's personal life, leaving viewers on the edge of their seats. Season 2 of Grimm confirmed that the structure of the series is some of the best that has ever been constructed in a procedural or a fantasy series. The plotting of Season 2 of Grimm used the careful worldbuilding of the prior season as a launchpad to introduce intense and emotional subplots that led viewers to emotionally connect to the lead characters of the series and root for them to succeed against their enemies. When it comes to Grimm, there is certainly no shortage of enemies.

2 Season 4 Elevated the Story and Worldbuilding to New Heights

Season 4 has a 100% Critical Score and a 93% Audience Score on Rotten Tomatoes

Season 4 of Grimm was rife with drama and exciting storylines that took the series in bold new directions. This season of Grimm saw Nick facing numerous challenges, including the loss of his Grimm powers for a notable duration of the season. This complex challenge prompted emotional and professional introspection from Grimm's protagonist, which elevated the season and series overall. The highest-rated episodes of Season 4 are tied at Season 4, Episodes 10 and 22, "Tribunal," and "Cry Havoc." A common theme between the two episodes tied for highest rated Season 4 is Nick's loved ones being targeted. This is especially true with Monroe and Rosalee, who are fan-favorite characters and have an innocent and warm air about them that compliments their inner strength. The adversity they face cuts deep for longtime fans and engages the viewers.

Season 4 of Grimm saw Monroe and Rosalee facing challenges against their relationship with a bigoted Wesen group who oppose their inter-Wesen relationship, harassing them, as Monroe is a Blutbad and Rosalee is a Fuchsbau. This storyline highlighted two of the best characters in the series while expanding on the socio-political beliefs in some areas of the Wesen communities. Grimm season 4 demonstrated the benefits of an inventive premise with rich lore and dynamic and likable characters, similar to shows like Buffy the Vampire Slayer.

1 Season 3 is the Perfect Grimm Season

Season 3 Has a 100% Critical Score and a 93% Audience Score on Rotten Tomatoes

Season 3 of Grimm saw the series find its perfect pace after spending the prior two seasons establishing the terrifying and creative world of Grimm. The season opened with a bang and a high-octane zombie storyline that saw Nick and all of Portland in peril. Season 3 of the series continued to grow the world of Grimm by expanding the political machinations of the mysterious Royal Family and demonstrating their reach in Portland. The highest-rated episode of Grimm season 3 is the finale episode Season 3, Episode 22, "Blond Ambition." "Blond Ambition" is the big wedding celebration between Monroe and Rosalee. The episode has a lot going for it and is more than just a simple wedding episode. Adalind's latest machination against Nick is a devastating blow to the Grimm. This dastardly plot sets the stage for the following season to pose never-before-seen challenges for Nick and his friends.

Season 3 has a fantastic slate of procedural episodes that included some truly scary Wesen with powers that posed a challenge for Nick and the gang to combat. The overarching plotline surrounding the Royal family brought history and intrigue and elevated Grimm to its perfect season. Season 3 of Grimm saw the series find the right balance and benefit from careful planning in the earlier seasons.