Hands down Ninja Scroll.

Though I also find La Blue Girl--an actual hentai series--to be more funny than it is sexy, because the plots and puns are just fucking amazing and the sex is (mostly) bog standard stuff. Except for that time a dude "air fucked" one of the protagonists with a bellows because they didn't want to have their dick cut off by her super vaginal strength.

Elfen Lied and Speedgrapher both immediately spring to mind. Unless you mean porn. Those are not porn.

Gushing Over Magical Girls.

Black Lagoon

Action/Drama

Nudity, Profanity, Smoking, Suggestive Dialogue, Suicide, Violence

Interspecies reviewers

Probably Berserk. Or maybe Ghost In The Shell + Ghost In The Shell: Standalone Complex seasons 1 and 2.

Both are truly mature in terms of writing as well as subject matter.

Ghost In The Shell gets really deep into the political ramifications of potential future technologies through the lense of a sci-fi action crime drama. 18+ for some extreme violence and naked/often scantily clad cyborgs with no nipples.

Berserk is mostly about found family and overcoming trauma through the lense of a guy with a huge sword in a medieval low-fantasy setting. 18+ for extreme violence, sex, sexual violence, torture, child abuse, I mean just most bad things people do are in there at some point or another. It's considered horror anime by some.

Ninja Scroll. Earns every penny of its rating

Psycho Pass. 18+ for intense violence

Does Takopi's Original Sin count? Definitely not one for kids.

Claymore

Of the ones I’ve seen, probably Berserk. And that’s without an actual anime adaptation that gives it proper justice.

Depends on what you’re looking for.

For me, I loved Golden Boy for the humor and stories. It’s not really like others with lots of fighting and violence. It’s 18 because of the mature sexually suggestive themes of the show. The second to last episode is the most sexually explicit with a woman doing stuff on a motorcycle and the first episode has tons of female body imagery that is very exaggerated.

So far everyone else here seems to share the anime that is more focused on fighting.

Highschool DxD is pretty amazing. Yes, it has copious amounts of nudity (mainly just breasts), but the plot, characters, and power system are actually so good! I generally only really like SoL and Romance anime, but sometimes the blend of power systems and SoL just balance out so well - A Certain Scientific Railgun is like that too!

You want 18+ for violence? Look up Inuyashiki. Doesn’t get mentioned enough. NOT to be confused with Inuyasha!

If you want risqué content… anime is not great for this due to censorship. If you wanna go hard, look up Redo of Healer. If you want something a bit more meaningful, look up Elfen Lied and TRY not to think of the context it unwittingly gives to SPYxFAMILY (specifically what it says about pink haired girls with horns and superpowers… more specifically the implication that Anya may be a diclonius).

Cyberpunk: Edgerunners

Redline

Gungrave

Nevermind, I apparently remember this completely wrong