Definitely, IMO - but I can't guarantee you'll like them, of course! :)
They're all very dark, in different ways, but there's a bit of black humour in there too.
I can't pretend to be any kind of an expert on Korean cinema - there's probably loads of good stuff that never even reaches the Western world. But I've seen most of the films which get UK/US releases. For a good place to start, IMO the directors to look out for are:
Park Chan-wook (JSA, Vengeance Trilogy, I'm a Cyborg, Thirst)
Kim Jee-woon (The Quiet Family, Tale of Two Sisters, A Bittersweet Life, The Good, the Bad, the Weird)
Bong Joon-ho (Memories of Murder, The Host, Mother)
Kim Ki-duk (The Isle, The Coast Guard, 3-Iron)
Kim Jee-woon and Bong Joon-ho are very diverse - between them they've done comedy, horror, mainstream action movies and serious drama. Kim Ki-duk deals with more serious stuff and Park Chan-wook probably has the most distinctive style.