What are the hardest PG/PG-13 movies and the softest R-rated films?

I just finished watching Cloverfield to find out that it was only rated PG-13. It was highly graphic for a PG-13 movie, probably the most violent PG-13 I’ve seen, maybe besides the animated DC Comics films. Other movies that come to mind for me that are hard PG/PG-13 are the Dark Knight, Poltergeist, and Jaws.For soft R’s, the Matrix felt way less graphic than the previous movies I mentioned, Planes Trains and Automobiles is another example which only got an R rating for the swearing scene, and the King’s Speech also for the scene where Colin Firth says the F-word multiple times.Those movies I think would’ve been fine for a PG-13 rating, they’re all less inappropriate than the stuff shown in movies like Cloverfield, Poltergeist, and Jaws, which I think have too much blood and violence for PG/PG-13 ratings.The films I mentioned are all the examples I could come up with off the top of my head. What are some other examples?Edit: I believe the Conjuring movies got an R just for being scary via /r/movies https://ift.tt/2vFIlru