The writing was thoughtful and intelligent, reminding me of some of the other dramas my parents watched on the major broadcast networks... and yet it was a superhero cartoon. I am far from the first person to say that the dialogue and conversations on this show are so good, it's almost a disappointment when the inevitable earth-shaking superhero battles break out.
But the show pulls those off brilliantly too. JLU has some of the most exciting fights you are ever going to see these characters wage outside of the comic books. There isn't a single live-action fight in any of the DC movies that even comes close to the level of action this show provides on an episodic basis - and I don't say that lightly.
The three seasons of this show are an absolute love letter to comics fans, with dozens and dozens of ancillary DC characters getting the animated treatment for the very first time. It not only works from a narrative standpoint, adding more diversity to the classic lineup of Superman, Wonder Woman, Batman, etc., but it also creates a wonderful Star Trek-like feel on the Justice League watchtower. Plenty of scenes show characters commiserating and enjoying their leisure time on this futuristic moon-based headquarters, and it adds a fantastic familial feel to the show that, again, makes it feel more like a mature sci-fi show or broadcast drama.
I treasure this show, and I also fear that the respect and gravitas this series showed towards the superhero narrative is a thing of the past. Sure, it's easy to have a cheeky Marvel movie where the characters crack jokes about how stupid they look, and it's easy to have a self-serious DC film that tries to make viewers forget the heroes are wearing costumes. But it's tougher to actually pay tribute to the original comic books in a thoughtful, developed way, to respect the men and women who actually created the narratives from which these pop culture icons have stemmed.
That's something this show did day-in and day-out, episode by episode. It's why it stands apart from other animated American TV productions, and why it deserves every bit of praise I can give it.