Justice League Unlimited:
I was not a huge fan of the previous Justice League series on Cartoon Network. Despite a few really good episodes, mostly I thought it was a pretty big comedown from the amazing Batman: Animated Series and the almost-as-good Superman: Animated Series. Not enough story, and the action, while good, wasn't good enough to keep up with it. The dialogue tended to be kind of "kiddy-fied" and so did the stories. Oh, I watched it, and I think I've actually seen every episode once (and the good ones a couple of times), but I kept thinking, "Damn... it could have been so much more."
If the first episode of Justice League Unlimited is any indication, it might be "so much more." A note perfect (well, his voice was too young for me, but that's quibbling) Green Arrow, some great chemistry with Captain Atom and Supergirl, Brimstone (from Suicide Squad, and that's major bonus points in my book), and a ton of DC heroes, both big and small, in the background? This is the DC Universe cartoon I wanted to see. Not to mention that they didn't lose the action, in fact Green Arrow in action was some of the coolest superhero stuff I've seen in animation.
Turns out maybe the hour-long two-parters were giving the creators too much room to move. With only half an hour, and a wider cast of characters, they seem to have tightened up the stories and the dialogue (I chuckled at several lines in the episode) while maintaining what worked about the previous series. Looking forward to seeing where it goes from here.