Yes, it's been posted before...but the thread was archived. I just found out about this film.
Wow. Like gory, violent, slick movies? This has it in spades.
To say I was impressed with this Korean film is an understatement.

Them Koreans are sick mofos.
I just saw
The Chaser the other night. It was on the same lines as the OP. Good foreign flick that I got into.
I'm not into horror movies, but as soon as I saw Oh Dae-Su from Old Boy, I automatically became more interested.