Teppu appears to be sort of known among the people I follow on twitter, but it should be hugely popular imo. Women's MMA with a protagonist who isn't ontologically evil but is kind of a huge asshole.

Not an anime but rather a manga: My Broken Mariko is a very angry short manga about the impact suicide and abuse have in someone's relationships. I ugly cried a lot after reading it.

Actually just looked it up and apparently there's a live action adaptation that came out last year, I'll have to watch that sometime.

Mai hime. https://myanimelist.net/anime/98/Mai-HiME/

Been years since I watched it. It seems well liked enough, so I guess I'm not the only fan, but I've never seen anyone talk about it. IIRC, it's a spin on magical girl anime but the pets are mecha. I like mecha and strong female characters, so it worked for me.

Malice@Doll, I doubt more than a dozen people on this site even know about this one, its just so bizarre and sometimes stomach churning

utena is the big one, but now i have irl friends who like it because i made them watch it. inu-oh i never even talk to people online about i just keep telling people to watch it. other big ones: hellsing ultimate, millenium actress, votoms, liz and the blue bird, vampire hunter d bloodlust, urusei yatsura: beautiful dreamer. all fantastic for different reasons that i will elaborate on later

::: spoiler this is later enough that no one is going to read this but still utena: my favorite show ever! surreal masterpiece that deals with gender roles, abuse, homophobia, and just incredibly sharp character writing. one of the gayest shows of all time

inu-oh: blind monks telling stories of ancient battles to appease spirits in medieval japan. new guy shows up with a dancer and starts telling them through the medium of hair metal. incredibly pretty movie

hellsing ultimate: vampires killing zombies and nazis and catholic priests. incredibly trashy, deeply horny, and ultraviolent -- the perfect show!

millenium actress: the life story of an actress mixed up with all the movies she's ever been in, with the filmmaking switching in style from movie to movie to her real life. just incredibly moving, just through the animation. iirc the last cel animated film ever

votoms: stock 80s action movie guy (think solid snake) goes through every action movie plot imaginable in a grim dark mecha future where the only robots are the shitty ones that blow up if you breath on them wrong.

liz and the blue bird: quiet yuri drama about a high school couple in band together. kyoani does stellar work here, just a gorgeous movie that i can't recommend enough

vampire hunter d bloodlust: like hellsing but gothic and brooding and not killing nazis

urusei yatsura beautiful dreamer: what if the cast of a wacky slapstick romcom got trapped in a lynchian nightmare? one of mamoru oshii's first directorial efforts, he knocks it out of the park

I find the sheer amount of manga / anime to be really overwhelming so I usually just stick to like "best of" lists. I have seen most of the big important ones but I'm sure I'm missing out on a lot of smaller stuff that is just as good.

serial experiments lain, ergo proxy, full metal panic (yea its got cringe school hijinks but its got really cool cold war soviet mecha badguys sometimes), special armored battalion Dorvack (on the borderline of so bad its good imo, its like a cheaper knockoff gundam, reuses a lot of animation sequences but sometimes has cool power armor guys show up later in the show), gundam IBO (look ima be honest i dont meet many people and i can barely get my friends to sometimes watch the original gundam series let alone this sometimes cringe but sometimes based spinoff about gay child soldier mercenaries that pretty much all die and their friends in the harem fantasy space yakuza, but despite all that the ending still gets to me and i cared about/related to the characters more than most shows. idealist but anti-corporate politics)

i really tried with princess jelly fish but the cross dressing trans panic gag bit was a bit too much

Sasaki and Miyano because I'd never admit to anyone I watched it and therefore have never met a fan of it

March comes in like a lion! My favorite anime!

I don’t really watch much anime, but do people know Yokohama shopping log/quiet country cafe? I watched that a few years back and was kind of mesmerized. If any of you anime heads have seen it and can recommend something similar that’d be cool.

Blue Period Manga/Anime.

Kemonozume

irl or even online? Do I get to count manga? If the latter and yes . . . uh, I don't think I've met a single person who likes Tenkaichi even though it's genuinely one of the best manga currently running. No Kengan Omega fans either, though it's not half as good imo. Also that one about the Detective Novel club, Versus, and, well, I guess I'd be here all day listing them all

If it's just anime, I've never met a Kengan Asura or Blue Lock fan, so there's that. Yes, I know Blue Lock is obviously proto-fascist, but it's still interesting here and there. I also think "The Misfit of Demon Academy" is unintentionally one of the funniest anime ever made and I don't know any fans of it. I can give it a thonk and come up with others if you're really interested, but I think that's a decent enough list to start.

PTSD Radio (manga) is another fun one. As an aside, my list is way shorter than it would otherwise be (Great Pretender, Paranoia Agent, a few others) because usually when I really like an anime I force someone else to watch it.

Oh! Blood Blockade Battlefront and Akudama Drive. Those are both really fun, well-animated action anime that I have never met a fan of.

Since you and another already said Princess Jellyfish, I’ve also been trying to get people into Dandadan (ok it’s not an anime yet) and I haven’t really run into anyone else who’s into it. It’s pretty damn great tho.