First off, I think the term "torture porn" is retarded. Its a trendy press catchword dreamed up by a bunch of media critics that have little to no actual understanding or appreciation for the genre.
Karma! I agree.
Anyways, I'm not drawn to any of these films in particular. I've seen parts of the
Hostel films (they didn't seem terrible, but they weren't that interesting either), and I hated
Saw and could care less about its sequels.
BTM mentioned
Funny Games but that movie doesn't really qualify as it breaks a lot of rules of these sorts of films, plus it isn't very graphic. It's uncomfortable as hell, though. I'd recommend watching it if one is curious, but I don't think it's as insightful as it's intended.