I haven't seen Martyrs or Inside. I don't think that I would like Matyrs, but Inside intrigues me.
I did see Haute Tension, which I thought was all sorts of hella retarded, but alot of people disagree with me.
Spanish horror is good too!
I LOVE this!
I do have to finish it one of these days.
This is also a good, but twisted old school Spanish horror film.
And if you want to watch something so Wonderfully bad, you can watch this Mexican wackiness.
[nomedia="http://www.youtube.com/watch?v=CQj-VkESu80"]YouTube - The Brainiac[/nomedia]