Bleak done well, and bleak done cheaply
Darkness has to be about something
The films that last in this category use bleakness to say something specific — about institutions, poverty, violence, the compromises people make. The ones that do not are simply unpleasant, and the difference is whether you feel you have understood something at the end or merely been put through it.
A quick test: if the grimmest scene were softened, would the film still make its point? If yes, the darkness was decoration.
Grit is a texture, not a genre
This list spans crime, war, drama and thriller, because what these films share is a register rather than a subject: handheld or desaturated images, moral ambiguity, endings that decline to resolve. That is why recommendations by genre alone tend to miss the mark for people who like this stuff.
It also means the range of intensity is enormous. A grounded crime drama and a genuinely punishing character study sit side by side here with nothing to warn you which is which except the description.
Space them out
Two of these in a row is one too many. They are made to sit with you, and watching them back to back flattens the second one into the first — you stop registering what makes each specific.
One a week, with something light in between, is how you get the most from this list. It is also the difference between finding these films bracing and finding them exhausting.