I love Eastern cinema, like from Korea, Vietnam, Japan, China etc. Consequently, some of my fave non-english language films are:
BATTLE ROYALE - visceral and relentless genius made by a 70 year ols man who hated adults. Just avoid the sequel made by his useless son
A TALE OF TWO SISTERS - remade into the slightly bland The Uninvited, this is a really scary adventure into a fractured mind
THE HOST - this Korean gem is what Godzilla could have been in the hands of a competent director
and to break from the far east, how about
THE ORPHANAGE - I mean, lets face it, kids are creepy, right?
DELICATESSEN - this black comedy about post-apocalyptic cannibalism has (thankfully, so far) escaped a Hollywood remake. It simply wouldn't work in any other language than French.