There are few villains out there who can claim to be equally as despicable and equally as charismatic as Kilgrave (aka Kevin Thompson, or Purple Man from the comics).
The only high-ranking villain on this list to actually have a superpower, Kilgrave possesses a form of persuasive mind control that forces everyone he speaks to do as they're told. Not only does he use this ability for detestable personal gain, most notably his romantic and sexual actions with an unwilling Jessica Jones, but even without this power, he's still an unrelenting miscreant.
Plus, the usually light-hearted David Tennant does an utterly amazing job portraying a vile psychopath who is also frustratingly charming. (Let's not forget that the man was very nearly cast as Hannibal Lecter not too long ago).
However, not only is Kilgrave a bad guy who's easy to hate, but he, like Cottonmouth and Wilson Fisk, has a twisted, but humanizing backstory. However, like them, he is also well past the point is no return and you can't wait to see him get his comeuppance for the Hell he's put people through.
He's a despicable corrupter of innocence who is devilishly entertaining, a huge part of the reason why Jessica Jones is such a fantastic show, and only just missed out on the number one spot.