Out of all the great, relatively obscure movies I've viewed recently, Valhalla Rising comes to mind. It's violent, bleak, gritty and Mads Mikkelsen is in it and he kills a ton of dudes.
Other than that, I would also recommend this horribly depressing but really well-made Belarusian WW2 movie called Come and See.
Other than that, I would also recommend this horribly depressing but really well-made Belarusian WW2 movie called Come and See.