If you enjoy the realism/grounded nature of the movie, it’s gonna be hard to find similar shows in anime, especially nowadays as everything is just romcoms or fantasy. Movies tend to be have more options in that category (check out the director’s other works).

In addition to Paranoia Agent, I would say maybe check out Monster? It’s a 60 something episode show about a doctor who saves a child’s life who turns out to be a serial killer, and now the doctor has to come to terms with killing him ‘for the greater good’ as someone who’s supposed to save lives. I haven’t finished it, but it also deals with nature vs nurture and some other stuff.

There are some genuinely creepy stuff in my opinion. I never liked the outro as a kid because I would be too scared to sleep lol.

Everything by Satoshi Kon. Millennium actress, paprika. Might not fit the exact genre but you’ll prob like them

In addition to the other Satoshi Kon stuff mentioned (Paprika, Paranoia Agent, etc.), I’d also recommend Angel’s Egg. It’s quite a bit more abstract/symbolic, but it’s a beautiful film imo. The art style was done by Yoshitaka Amano, who’s famous for his amazing Final Fantasy concept art, and the music (by Yoshihiro Kanno) is quite good too. It’s not very long either, but it really left an impression on me.

EDIT: Oh I almost forgot, but the first episode of Oshi No Ko is basically a whole movie and shares a lot of similar themes to Perfect Blue, but with a bit more humor. The story starts out a little weird, but stick with it. It gets better and better. Also don’t look up anything on this before you watch it. It’s best to go in completely blind.

Serial Experiments Lain isn’t obscure by any means, but it has earned its status in the canon. It’s esoteric, it’s paranoid, it has confrontations with mirror selves and a complete breakdown of consensus reality.