I think Britney's transformation over the years is what's shocking. I'm not knocking her, but she's gone from one extreme to the other (it seems).

Manson's character is to shock, though. That's what he does - he wants that reaction out of people. Its all for show, though.

To answer the question, I think Manson is the one who really shocks most people because he isn't "the norm" and a lot of people are disgusted by him. I like him.