The last shock/snuff video I voluntarily watched, ~3 years ago, was one of some animals getting skinned alive at what looked like a third-world marketplace (and still alive after their skin had been ripped off). Among them, I think, were a dog, a raccoon and a lamb.
I used to have much more curiosity about things like that as a teenager, and would go to rotten.com or whatever on occasion, but after a certain point seeing that stuff began to feel like having toxic waste dumped in my brain and polluting my psyche. I don't necessarily have anything against the idea of being desensitised to it, but I kind of sense that feeling revulsion to it is a sign of maturity.