I've made it a point to at least watch every film that Tartan Asia Extreme releases, they put out some pretty good movies, even though once in awhile there will be a boring sucky one.
Have you seen Versus? It's a fun martial arts zombies in a forest type movie. More action than horror though.
http://us.imdb.com/title/tt0275773/
Um, I'm trying to think of some others, I'm at work so I can't just look at my dvds. I've seen so many, I've become a big asian flick junkie in the past couple of years.
There's one, called Infection (Kansen), that I thought was just awesome, very layered movie that was kind of hard to understand on the first viewing, but it had killer atmosphere and a good story.
http://us.imdb.com/title/tt0418778/
I can't remember but there's someone posted on here that they like Phone alot, it might have been you. There's another flick by the same director called Nightmare (Gawi) that's pretty good.
http://us.imdb.com/title/tt0269266/
Acacia is great, I really liked the story and the ending.
http://us.imdb.com/title/tt0380164/
There's a new movie by the director of The Grudge that just came on, I haven't been able to find a copy of it on Ebay or anything yet though, although apparently there's a Region 2 release coming out of it later this month, i may try to buy it. It looks really interesting. It's called Reincarnation (Rinne).
http://us.imdb.com/title/tt0456630/
Plus, there is this haunted girls school series:
Whispering Corridors
Memento Mori
Whishing Stairs
Voice
They aren't bad, the first two are the best ones. They are unrelated except they each involve a haunted girl's school and of course a little lesbianism every once in awhile.
http://us.imdb.com/title/tt0241073/
http://us.imdb.com/title/tt0266075/
http://us.imdb.com/title/tt0370082/
http://us.imdb.com/title/tt0470967/
Last but not least, the Eko Eko Azarak Trilogy. These you can actually find at Best Buy for like 15 bucks in a box set. It's well worth it.
http://us.imdb.com/title/tt0112939/
http://us.imdb.com/title/tt0116178/
http://us.imdb.com/title/tt0130650/
There is a fourth one, but it sucks and is completely different from the other three.
All of these flicks you should be able to at least get on ebay though most of them are official U.S. releases.
Anyways thats all I can think of, hope this gives you some ideas of other flicks to watch.