R

Memento's "R" rating is all about the violence. Okay, maybe there's a prostitute, and maybe she snorts a line of cocaine. And sure, there are a number of F-bombs and Natalie has some not very nice words to say about Leonard's wife, but mostly it's the violence.

We see a man strangled to death, a man shot in the head, another man beat up and bound, and some general roughhousing—you know how boys (with anterograde amnesia) are.