Fictional characters don't scare me. It's not that I'm scared of Gacy himself but, the thought of what people hide under makeup or costumes is pretty scary.
What made Pennywise so scary in my opinion is that the tv series IT was broadcast on network tv and thus I was allowed to watch it when I was a kid and I was afraid of taking a shower for weeks because I was sure Pennywise was in the drain.
He's the only one on the list that I find scary. I'm not afraid of clowns, but John Wayne Gacy was real, so that makes him scary. The other ones make me laugh.
Well I am pretty sure Pennywise was based off of John Wayne Gacy...so actually John Wayne is scarier since he was real. Pennywise freaks me out though.
Were I that kid, I'd need a change of pants and someone who knows how to work a defibrillator nearby.
Arrrrrrrgggggghhhh!!!!