Dr. Doom should be pretty familiar to most people. He's what I would call the Fantastic Four's most recognizable villain. He was in the movies, after all. The movies don't even scratch the surface on what this guy is capable of though. He's the type of guy who messes around with other-worldly beings. Don't go to one of his house parties. Nobody chill will be there, and you'll end up being killed or enslaved.
Most recently Dr. Doom went after Thor's hammer after the fall of Asgard. He was so sure he would be able to wield the hammer, but guess what? He couldn't lift it. How frustrating is that? You're so powerful that you've even died and been resurrected, but you can't even lift Thor's hammer. I guess worthiness has nothing to do with how many lives you've ruined with your power. Sigh.