Emperor Palpatine, he had an entire galaxy under his control.

And I'd like to give a shout out to President Snow. I just saw Mockingjay and that guy us a real asshole.

Satan from his role in the Bible.

I am the greatest super villain.

Your complete inability to find any evidence supporting this, and the idea you have that super villains are preposterously fictional are both by my design, and are among the reasons I'm the greatest. Nobody will believe this post either- until it's far too late. History will note this as a sign that should have been heeded, but went ignored due to the collective hubris of humanity.

Muhahahahahahahahaha!

Thanos. Wielder of the infinity gauntlet, destroyer of the universe, and even had a thing with Death herself. Enough said.

Palpatine. Chancellor or emperor, he is the worst. Big no no if you meet him. you might actually die. that is why Palpatine is the greatest super villian

Unquestionably Elmer Fudd. His single minded focus on murdering bugs bunny, with unwavering determination stand as an example for all of us. A very close second would be Wile E. Coyote.

Rita from the Mighty Morphing Power Rangers.

She could make Super Villains even bigger and stronger with her staff ...

Johan Liebert. Being a villain from childhood makes him extra scary. He's not super powered or anything, but the story makes the villain, not the powers.

Bowser... Considering how many times I THROW HIM INTO LAVA AND EXPLODE HIM AND HIT HIM WITH METEORITES, how does he still survive to capture Peach?

I'd ask waht constitutes as villain, but I guess even without that information, it'd be generally agreed that Galactus is a villain.

I consider him to be the greatest villain because everything about him, from the way he appears, to his purpose in the universe embodies fear, something I consider to be necessity in a villain. He has no physical body, he simply appears to us in whatever way our minds can process him, and for Earthling humans, that just happens to be a giant, ripped, purple armor wearing humanoid. As for his purpose, well he basically exists as the life garbage man of the universe. Devouring all life, storing the energy that will go back into recreating the big bang, after the big crunch happens.

Honorable mentions go to:

Dr.Doom for his impeccable thirst for power, that he'd stop at nothing to achieve.

Joker for his super sanity, and overall shenanigans that both disgust me, and make me laugh.

Lex Luthor, just because he's anti-supes.

I would have to say the atheists. They are demons inside of a human body.