Shin Kujakuou

Before the likes of Saint Seiya, Dragon Ball Z and Pokemon conquering the kids in the west, it was actually Akira that opened the door and made people realize that the cartoons coming from Japan weren't what you would expect from Disney or your TV channels.
A huge flood of VHS tapes came showing animations with mature themes, absurd plots, and enough graphic sex and violence to make parents freak out... what a glorious time!
They don't make cartoons like this anymore.

This is a comprehensive list with stuff from very good to very trashy, but all in the same spirit.
Some early 00's also included.

ps: I also recommend, but can't include here, Kage (OVA).

Glorious 80's and 90's (Sci-Fi, Neo-Noir and Crime Drama)
https://myanimelist.net/stacks/30604

A list of Action anime, of the guns, fists and violence variety, where you don't have to think too hard nor focus on plot development and character development; if you're looking for outstanding stories these might not be for you.

Trying to give some action to action anime that may be lost to time or just haven't generated an audience, all in the while mixing in some big hitters that you might have missed.

Rintaro is the pseudonym of Shigeyuki Hayashi, a well-known director of anime. He works frequently with the animation studio Madhouse (which he co-founded), though he is a freelance director not employed directly by any one studio. He began working in the animation industry—at age 17—as an in-between animator on the 1958 film Hakujaden. His works have won and been nominated for multiple awards, including a nomination for Best Film (Metropolis) at the 2001 Festival de Cine de Sitges.

Rintaro is a fan of science fiction, and has been influenced by American westerns, gangster films, film noir, and French films. Additionally, he was influenced by Osamu Tezuka, and worked with him on Kimba the White Lion and Astro Boy. He said that when he was making Metropolis, which was based on Tezuka's manga of the same name, he "wanted to communicate Tezuka's spirit". Rintaro personally introduced the film at the Big Apple Anime Fest in 2001, where it was screened before its theatrical release by TriStar Pictures.