If anyone has seen at least one of these 3 movies could I have your honest opinion?

There are 3 movies that I hear are (were) truly disturbing. They are: Caligula, I Spit On Your Grave and The Last House On The Left. I've read reviews about them that claim that they are "so disturbing" and "not for the faint of heart" and "so realistic". I want to rent all three but I'm a little nervous. Are they truly as disturbing as critics claim they are? Mind you, they did come out in the seventies but then again so did The Exorcist and that movie genuinely disturbed me! I would appreciate anyone's answer that has actually seen the movie(s). Thank you.