I usually don't like zombie films, I prefer slashers. But I really liked "Rec". I love the whole "Blair Witch"/"Cloverfield" type of filming. Makes it feel more realistic. I just bought it on Blu-ray and I'm gonna watch part 2 tomorrow. :) Can't wait!
To answer your question...I love all types of horrors. I love gory horrors and psychological horrors and horrors with great atmosphere. I do not discriminate with horrors. I loved REC and in fact it would probably be in my top 5 for horror movies. Another one in my top 5 would be 'Session 9' which has almost no blood in it whatsoever. It is all about the atmosphere.
But I do enjoy a good slasher. I'm not sure why, I just find it to be really cool to see a lot of blood and gore in a movie if it's done right (yea I know now I sound like a psycho killer). For example the movie 'Hatchet' was very gory but I loved it. People's limbs being hacked off and their heads being twisted off...I don't know, just something about it that I like. They usually don't scare me...I just like to see the blood and guts. Although the original 'Halloween' would be considered a slasher and that still creeps me out. That probably doesn't help to answer your question much but oh well.
You mentioned that you like a "few" slashers. Care to say which ones?
I've never seen Maniac or Suspiria. I've heard lots of things about Suspiria, about how good it is. But I've watched the trailer for it online and it really looks like a movie I would not enjoy so I have held off on watching it. The original Texas Chainsaw Massacre is a classic and very awesome. I own that on DVD.
I also own Audition. I gave it a 5/10. It was different, and I sort of liked it...but it was kind of slow to me. I think I just might not enjoy asian horror. I've tried Ju-On and hated it and Audition also wasn't that appealing to me. A good asian film is 'Old Boy' although that is not horror.