Which villain has the most compelling dialogue? Why do you think so?

By "most compelling", I mean, dialogue that actually makes you fearful of that villain and makes you think, "Ok, this person is actually evil."

Right now, I'm struggling to think of my own examples; I guess that's why I'm asking you guys. I can't truly think of a villain that has ever put an actual fear in me.

Ok, at this point I'm just trying to fill in the character limit. Is this enough? I don't want to resubmit this again.