Well, that question may be a bit hard to answer, especially considering the creation of the internet. So, I guess I'll put mine into two parts:
1. In terms of the internet, I stay away from certain subjects. Obviously child porn is somewhere that I don't go anywhere near, and I avoid snuff films too. However, that hasn't stopped things from slipping through. Thankfully I've seen none of the latter, but on the internet one of the worst things that I saw was probably someone getting axed in the head, or a Saudi execution (which is done by beheading if you were unaware). I've probably seen other things too, but those stand out to me. I've also read some things by white supremacists, Nazis and murderers that have not been very good. I've seen some weird ramblings by those types of guys.
2. Speaking of real life, I have fortunately gotten off a lot more easily, because I can tolerate violence a lot less in real life. While it may disturb me to see killings on a screen, if I saw one in real life I'd probably pass out. Maybe seeing someone die while I was at Harvey's one time? I don't know. It's good that I haven't seen as much in that respect.
So, what about you guys?