Pathologic is a game which has been major in Russia, but not elsewhere. It's got more bleak than a normal person can imagine. And atmosphere. And clever ways of cranking up the tension, including that your character's mere maintenance (food and sleep and such) is a constant challenge. It's a game where when you finally get a revolver, your best choice is to trade it for a little food.
Normally, game reviews all blur together for me. I expect to remember this one, but I only recommend it if you have at least some taste for horror.
If you intend to play the game, I recommend skipping the third section of the review. It gives away a major emotional/thematic twist.
Link thanks to andrewducker.