Best cartoon series for adults? Recommendations needed.
 

I have not watched cartoons since I was a kid, but I recently started watching Batman Animated and Superman Animated, and I really enjoy them.

I plan on picking up Justice League when it comes out.

Are there any other really excellent series I should look into?

You might want to look into some anime series or movies.

I find much of the Adult Swim line-up to be hilarious. Particularly Aqua Teen Hunger Force or Sealab 2021. And to a lesser extent Harvey Birdman: Attorney at Law. These are different than Batman: TAS, but still enjoyable and adult-oriented.

Harvey Birdman
Futurama
Samurai Champloo
Paranoia Agent
Venture Brothers
Ghost in the Shell: Stand Alone Complex
Aqua Teen Hunger Force
Southpark
Drawn Together
DuckTales

Pretty much anything on Cartoon Network after 11 p.m.

Sorry I don't watch many of the superhero oriented ones.

Pinky & the Brain

South Park is pretty cool.

Slightly off topic, you could try movies like Final Fantasy, Anamatrix

Not sure if this is what you're looking for because they're all adult comedies, but they are cartoon series for adults:

Family Guy (Probably the funniest show I've ever seen)
Futurama
Beavis & Butthead
The Simpsons
South Park
SeaLab 2021
American Dad

Oh yeah, here's a non comedy one that is DEFINITELY for adults: SPAWN.

My best friend also loves "Aqua Teen Hunger Force".

The original Teenage Mutant Ninja Turtles

Since you dig the DC universe, I am pretty glued to the screen for new Teen Titans episodes.

A few that are generally aimed at kids, but occasionally have little things an adult might notice:

The Powerpuff Girls
Grim Adventures of Billy and Mandy
Fairly Oddparents just gets bizarrely surreal at times.

Nicktoons plays Ren & Stimpy late at night. Those have held up a lot better over the years than I would have expected.

I love watching these with my daughters. I particularly liked the FOP movie, Channel Chasers.

i really enjoyed the Gargoyles series back in the day.

Stroker & Hoop

Exo-squad

Roughnecks

Dexter's Laboratory

Among anime, I'd highly recommend starting with Cowboy Bebop.

^^^
That's a good one too.

I forgot to mention Invader Zim.

Daria's not too bad either.

Drawn together.

Agreed. And hopefully we get new Venture Brothers soon.

Make sure to catch The Tick on the Disney channel.

Barely lasted a season, and only available on DVD via Canada, but one of the funniest animated shows I've ever seen...

CLONE HIGH

..certainly not for the kiddies, either, even though it did originally air on MTV.

If anyone's looking to get it, try the following sites...

videoflicks.com

Amazon.ca

a&b sound

I gotta throw some love in here for Roughnecks. The entire series is on DVD.

Can't believe I forgot Invader Zim and Dexter's Laboratory. Dexter has one episode in particular that really breaks out of it's genre and becomes a true science fiction story. I'm not sure of the actual ep title, but I believe it's "Omelette du fromage".

Doh! Forgot Samurai Jack! Might not be on anymore, but is on DVD. Wonderful stuff from the guy who would later make the incredible Star Wars Clone Wars animated shorts.

If you are going to throw Dexter in the mix, then I have to throw Powerpuff Girls in here as well, especially the earlier episodes before Cartoon Network decided to market the show to little girls. I first learned about the series in an ad in an alternative music magazine, and it was clearly geared more towards a college aged audience, and would have probably landed on Adult Swim if AS had existed back then. (and preferably kept the name "Whoopass Girls" for the AS version!)

Spawn: The Animated Series
Gargoyles
Spiderman: The new animated Series (MTV)
Batman Beyond
Berserk

All the titles I really enjoy have been mentioned here but I shall compile a list:

Batman: TAS
Clone High
Clerks: Uncensored
Family Guy
Futurama
Harvey Birdman
Invader Zim <---This show is amazing
Samurai Jack
Sealab 2021

others I remeber enjoying but have yet to see on DVD either to not being released or not enough money:

The Tick
Gargoyles
X-Men

Assuming you already know about The Simpsons and South Park...

Some of my favorites:
Aeon Flux
Clerks: Uncensored
The Maxx (Not on DVD)
The Tick (Not on DVD)
Bill Plympton's Plymptoons
Triplets of Belleville (Movie)

And my favorite Anime:
Cowboy Bebop
Serial Experiments: Lain
Now and Then, Here and There
Boogiepop Phantom
RahXephon
Noir