Founded by Arlene Klasky and Gabor Csupó, studio Klasky Csupo dominated the American animation landscape throughout the '90s and early 2000s. After making it big by producing the debut seasons of The Simpsons, the studio went on to churn out hit after hit of lovingly ugly alternative works of art with a focus on character like Rugrats and Ahhh!!! Real Monsters, becoming not only the golden goose for Nickelodeon, but one of the most prominently defining creative forces on television.

Between diapers, ducks and surfer dudes, here is a ranking of the eight Klasky Csupo animated series!

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8. All Grown Up (2003)

Putting it lightly, All Grown Up was a show that was unneeded. Born out of the original Rugrats series’ 10th anniversary special, "All Growed Up" serves as a times-skip sequel to the classic Nicktoon, following the Pickles babies and company into pre-adolescence as they navigate mundane suburbia and middle school. By aging the Rugrats gang up, the appeal of the characters and the original premise had been lost entirely and replaced with the kind of by-the-numbers teen sitcom that had already been dominating Nickelodeon with shows like Drake and Josh and Zoey 101. All Grown Up’s biggest fault was that it felt like it was born out of an executive think tank that sought to make the long-running series new again without understanding what made its childlike worldview special in the first place.

7. The Wacky Adventures of Ronald McDonald (1998)

To answer both questions, yes, this is real and no, it is not something collectively imagined in a childhood fever dream. Sold as a series of VHS tapes at participating McDonald's restaurants in the late '90s and early 2000s, The Wacky Adventures of Ronald McDonald delivers exactly what it promises as a corporate promotion and more. Formatted as a hybrid live-action/cartoon show akin to The Super Mario Brothers Super Show, the series takes the iconic fast-food clown and his menagerie of mascot friends (Hamburglar, Grimace, etc.) into the animated McDonaldland where they go on outright bizarre misadventures, complete with ghosts, aliens and deserted islands. For what ostensibly was produced as glorified in-box Happy Meal prizes, Wacky Adventures managed to make more of an impression with absurdity and borderline hallucinogenic style than expected to make it worth a nostalgic revisit.

6. Rocket Power (1999)

While most Nicktoons have been able to maintain their timeless quality decades after their debut, Rocket Power is firmly and charmingly a product of its time. Debuted in 1999, and boy does it show, the series follows a team of SoCal kids who live every day to the extreme as they surf, skate and play up and down their beachfront pier town. Most series of its kind reside in a town that can discreetly be a suburban every town in Anywhere, USA, but Rocket Power proudly takes place in a California beach town and lovingly caricatures the grungy off-color characteristics of its urban landscape and citizens. Looking at any typical episode today, there is also no shortage of early 2000s slang, music and humor that make it a charming capsule of the era and its setting. While on the surface the series may come across as a hollow attempt to appeal to hip youth culture and extreme sports, the characters and their relationships made each episode a joy to watch even without the sports action.

5. As Told by Ginger (2000)

As Told by Ginger is the adolescent chronicle that All Grown Up was trying to be. Created by Emily Kapnek, the series followed Ginger Foutley (Melissa Disney) and her fellow social outcasts as they take high-school one day at a time. As with other shows of its kind like MTV’s Daria or Nickelodeon’s own Hey Arnold, Ginger took a compassionate look at the trials of young adulthood. What made Ginger endearing was in how it sought to disband the constructs of cliques and societal preconceptions. While Ginger and her friends were effectively wallflowers, they were able to mingle with friends and form relationships with classmates well outside their comfort zone and even income level. Just as the Macy Gray theme song says, Ginger championed that regardless of social standing, friendships can still be made with people who are “different, yet exactly the same”.

4. The Wild Thornberrys (1998)

The Wild Thornberrys is the most well-rounded animated show about nature out there. The series follows a family of documentarians who travel around the world to get up close and personal with the animal kingdom, especially their youngest daughter Eliza (Lacey Chabert), who is able to secretly speak to animals in their tongue. Each episode centers on a new kind creature and location as Eliza, along with the viewing audience, learns more about their place in the ecosystem and how they survive in it. Deceptively educational, the series made it a point to feature animals and locations that ventured far past what its young viewership was familiar with, from isolated Galápagos turtles to Asian snow leopards. Over five seasons, one movie and a Rugrats crossover, Wild Thornberrys was able to be just as tastefully sensitive about nature’s balance as it was a rollicking adventure.

3. Aaahh!!! Real Monsters (1994)

Along with a revolution of creator driven animation, the '90s saw a spike in cartoons that indulged in the macabre and the disturbed. In the decade where Tim Burton and The Addams Family popularized family-friendly suburban terror, Aaahh!!! Real Monsters became Nickelodeon’s monstrously modest hit that made the horrifying hilarious. Predating Pixar’s Monsters. Inc by nearly eight years, the series stars a trio of aspiring monsters as they prowl the sewers and up to the human world to meet a daily quota of scares and mayhem. The charmingly grotesque design language that trails across each of Klasky Csupo’s productions is fully embraced here as the series features some of the most distinct and appealingly hideous looking monsters to come out of '90s animation. With more gross-out humor and visual gags than can fill a sewer pipe, Aaahh!!! Real Monsters is a frightfully fun Nicktoon.

2. Duckman: Private Dick/Family Man (1994)

One of Klasky Csupo’s only adult series, Duckman was far and away ahead of its time. Created by cartoonist Everett Peck, the USA series starred Jason Alexander as a loudmouthed water fowl who, among a laundry list of obscenities and atrocities, solves crimes as a private investigator partnered with a pig and two politically sensitive teddy bears. In an age where adult animation was just starting to take shape in the wake of The Simpsons, Duckman’s fractured view on humanity through the eyes of manic-depressive duck was able to balance biting satire and genuine sincerity across each of its 70 episodes more than other short-lived adult cartoon hopefuls have then or since. The focus lesser series have put into being over-the-edge and crude Duckman successfully put into characterization, making the lewdness of its comedy hit harder through the show’s brilliant writing and voice acting.

1. Rugrats (1991/2021)

Unquestionably the studios’ most iconic work and one of the three inaugural Nicktoons, Rugrats was the defining show for the Nickelodeon '90s. The series showed life from the perspective of babies and how they naively interpreted everyday scenarios as world-shaking events. The second-longest running Nicktoon behind SpongeBob SquarePants, Rugrats has been able to amass a tenure of nine seasons, three movies and a 2021 CGI reboot purely by the charming strength of its characters and wise beyond its years writing. Despite their age, Tommy, Chuckie, Angelica and the rest of the characters had fully developed personalities that worked off each other naturally, whether it was in telling the story of Passover or in treating every mundane activity into a larger-than-life adventure. The series appealed to kids and adults for the totality of its run for how much the characters spoke to every generation, with even Steven Spielberg describing the show as “the TV Peanuts of our time”.