Aside from Akira, and the few Ralph Bakshi movies I've seen, I don't watch a lot of animated movies made for adults. TV shows on the other hand, I'm a big fan of Rick & Morty and Bojack Horseman. I also still like South Park, even though it can be hit or miss.
My favorite adult animated movies:
Watership Down.
American Pop.
Heavy Metal.
Fire and Ice.
Wizards.
Waltz with Bashir.
Fantastic Planet.
Lightyears aka Gandahar.
South Park Bigger Longer and Uncut.
Tripletes of Bellville.
Starchaser Legend of Orin.
Felidae.
Fritz the Cat.
Chico and Rita.
When the Wind Blows.
Batman Mask of the Phantasm.
Batman Sub-Zero.
Antz.
The Dark Knight Returns.
Batman Beyond Return of the Joker.
Rock and Rule.
Persopolis.
Ninja Scroll.
Akira.
Golgo 13 The Professional.
Perfect Blue.
Wicked City.
Vampire Hunter D 1 & 2.
Paprika.
Princess Mononoke.
Fist of the North Star.
Metropolis.
Cowboy Bebop the movie.
Shows:
The Simpsons (1 to 10 seasons).
Spawn.
Bojack Horseman.
Regular Show.
Rick and Morty.
Cowboy Bebop.
King of the Hill.
Futurama.
Archer.
Aeon Flux.
The Critic.
Duckman.
The Head.
Dr Katz.
Castlevania.
Black Lagoon.
Ghost in the Shell Stand Alone Complex.
The Maxx.
American Dad.
Claymore.
South Park.
Golgo 13 the series.
Trigun.