I think for consistent quality Asian horror beats American horror. In my opinion American horror has some of the highest highs and the lowest lows. These highs include The Shining, Dawn of the Dead (1978 version), Blair Witch and The Thing. So I prefer American horror overall.

Audition is a terrific Asian horror movie though. One of the best. There is also an independent movie called Tetsuo the Iron Man which must be one of the most unintentionally terrifying things I've ever witnessed.