So good that it led to a generation of kids who were annoyingly pretentious about filmmaking (it's me, I'm kids).
It's a miracle that an animated series like Samurai Jack was ever made—much less allowed to endure—on a children's network: barely any dialogue, action that approaches the realm of the avant-garde, and storytelling that doesn't rely on jokes or moral lessons. For its first four seasons that aired from 2001 to 2003, it barely had a plot to speak of either, becoming a Sisyphean series of adventures through an increasingly strange universe that only emphasized Jack's determination to finish his greater mission. And the more that the titular samurai would face off against his stoic robot adversaries, the more visually expressive these fights would get, the show constantly finding new ways to communicate purely through gorgeous, minimalist animation.
Only in the show's unexpected fifth season (released much later in 2017) did Samurai Jack really commit to telling a story and developing the protagonist as an actual character—putting him through a crisis of faith and having him face his repeated failure through the show's previous seasons. The results weren't flawless, with a rushed conclusion and a romantic interest who never quite came into her own. But it would be difficult to overstate how ambitious this whole project was: a genuine sci-fi/fantasy epic that never compromised on its vision.
Samurai Jack's 2017 comeback was so surprising not just because of the improved quality of its animation (while still staying true to its classic style) but also because of its maturity. Season five is incredibly violent and even more dynamic with its action, with Jack facing off against flesh-and-blood enemies in brutal fashion while sustaining injuries that actually feel like a cause for concern. Finally seeing our hero bend to all the pain he's endured is unexpectedly affecting, and for arguably the first time in the series, you truly begin to feel how powerful Aku has become in comparison.