Aphex Twin should have won this poll BY A MILE. The only reason they didn't is because too many people don't know them.
And this is not even opinion, it's a fact. Anybody who has watched some of their music videos like "Windowlicker" (harmless), "Rubber Johnny" (disturbing) or "Come To Daddy" (****ING DISTURBING) ought to know that.
I warn anyone who doesn't know them yet and is sensitive not to watch "Come To Daddy" before bedtime.
PS.:
Manson is child's play compared to the Aphex Twin videos I've named in this post, except for MAYBE Windowlicker depending on personal opinion.
PPS.:
In hindsight and after re-watching both of them one more time, I honestly think "Rubber Johnny" is actually a lot creepier than "Come To Daddy".