Easily Inside.
The Hills Have Eyes was surprisingly a great remake, and easily one of the best horror movies from the last decade, but its "disturbance" doesn't come anywhere near matching Inside's. I mean, just the final shot of Inside, with this psycho woman burnt up to pieces holding a newly born baby while rocking back and forth on a rocking chair is more visually disturbing than anything The Hills Have Eyes has to offer. Not to mention all the horrific stuff we had to witness getting up to that point of the movie.
Moreover, Inside being more realistic plays a part in it as well. We all know a mutant family like the one in The Hills Have Eyes could never exist; however, there are plenty of terrifying stories out there about women who go batshit crazy when trying to get a baby when they can't have one of their own. That fact made the movie Inside feel that much more real, whereas The Hills Have Eyes you knew the entire time nothing like that could ever happen.
