it's a tie with carrie and several movies of the death wish series, i can't remember which was first. carrie scared the living shit out of me, though, and charles bronson was a personal hero for a while, so their respective emotional impacts were pretty different.
incidentally, i seem to remember movies in the 80's being more free with their graphic/sexual content. seemed like every time you turned around there was a nude scene in a movie or a guy getting gratuitiously decapitated, and no one really made a big deal out of it. it could bet that, since i was a kid at the time, i wasn't in touch with what people considered "pushing the line".
i think our society makes WAY too big a deal out of graphic content in movies, especially sexual. that's a whole other can of worms, though....