Beware The Batman is the CGI show. Caught an episode or 2 on tv so went out and bought the dvds. Is aimed at an older audience. Probably why it got canned. Was actually good we thought.
And if you want dark Batman stuff, might I suggest The Dark Knight Returns cartoon movie. They separated it into 2 parts but you can track down a release that put it back together. You'll notice alot of references of this Frank Miller story in the upcoming movie. Kinda why I am excited for the live action movie because this comic story is just brutally awesome. And Year One is also another Frank Miller story, great cartoon and worth watching too.
And another dark comic that is being made into a cartoon movie is The Killing Joke. It is the origin story of the Joker and it is quite quite brutal. And topping it off, they've given it a go ahead for an R rating, only way it can be done if you've read the comic. And if that ain't enough, Conroy and Hamill will reprise their iconic roles. Hamill, while retired from the Joker, always said he would come back for this role. Tim Burton, and a number others, have cited this story as inspirations.
Sorry for the essays, but I am a massive Batman fan