
I liked Moritat, but lots of people hated it, so idk. Banana Fish is now better known with the more recent anime adaptation, and the manga's drawing style dates it a lot, but whether you watch the anime (VERY good, but I prefer the manga) or read the manga impacts your experience. Sry all the other I know are v mainstream

Moritat was my first manhwa heh
I really enjoyed it, but maybe because I didn’t really have standards back then.
To the sea is one of my favorites! I’ve also watched the anime adaption of banana fish already. Darn it, I think it’ll take a while to find comics I haven’t read yet... ╥﹏╥ thanks anyway folks :)

You won't find that here, but check out the "In these Words" series by TogaQ and Kichiku Neko. Those two are a dream team concerning dark and fucked up shit that is also clever. But also enormously graphical ;-) They have a lot of other stuff besides the series. And TogaQ's art is to kneel down. High class. They also have their own website:
http://www.guiltpleasure.com/

Encompasses everything. http://www.mangago.zone/tag/Dark/

I wouldn't call it underrated but I would call it sublime. It damn near wrecked me. http://www.mangago.zone/read-manga/itou_san_kuraka_sui/
What are some underrated/lesser known dark bl comics? Just some good psychological stuff...
(Shoujo comics are fine as well)