I watched a few episodes of League at Wondercon and... it was fun. Not Earth-shattering, or super clever, or outrageous. But good fun. In a nutshell, the League Of Super Evil follows a group of supervillain kids living in a house together. There's Voltar, their evil leader; Red Menace, who's green instead of red and is the group's muscle; Doktor Frogg, who's the group's mad scientist; and Doomageddon, the dog.
The show avoids a lot of the cliches you'd expect from a set-up like that. For one thing, the L.O.S.E. spends most of its time fighting other supervillains, not superheroes. (Although there's a pretty hilarious send-up of the Mighty Morphin Power Rangers in one episode.) For another, the plots mostly don't revolve around the supervillains trying to take over the world. More often, Voltar wants to impress the other kids in the neighborhood, or win a bet or something.
In one episode, Voltar brags to the neighbor kids that he gets a zillion TV channels... so he sends Doktor Frogg up into space to rig a special satellite to get a zillion channels for their TV set. And in another episode, the tiny Voltar steals another supervillain's giant suit of armor so he can beat another kid at a basketball slam-dunk contest.... but that attracts the attention of the afore-mentioned Power Rangers clones. In a third episode — and by far, the funniest I saw — Doktor Frogg builds a machine that will plug up all the toilets in the city, unless the city agrees to his demands... but Doktor Frogg has no clue what those demands are.
Oh yeah... Did I mention there are a lot of poop and fart jokes? Those pretty much form the underpinnings of this series, which is not at all a bad thing. At the Wondercon screening, at least one audience member mentioned it was reminiscent of Ren And Stimpy in terms of its aesthetic, but it's a lot gentler and sillier. The characters are basically losers, who stumble around in their giant suits of armor or go to ridiculous lengths to prove they're badass. According to Wikipedia, some other storylines include "selling watered down lemonade" and trying to get a table at the most elite supervillain restaurant in town.
It's cute and fun, and will probably spawn a cult following. The first episode is tonight at 9 on the Cartoon Network.