38. Ras al Ghul Batman Begins
It is often said that the most frightening villains are those who believe themselves to be in the right. Ras al Ghul seems to fall into this category, although he isnt particularly frightening. This excellent antagonist has entirely noble motivations. He wants to improve the world, but it is his sick means that make him an evil character. Ghul is willing to allow Gotham to not only be destroyed, but tear itself down through fear. He intends to kill innocent people in order to purge society of the city's filth, but not humanely. They will suffer and writhe until eventually their own delusions cause them to kill or be killed. Thats pretty harsh.
37. Magneto X-Men Series
Magneto is one of the most compelling villains in superhero lore because, at heart, he has a very righteous cause. Magneto hates humanity because he has been subjected to experiments during World War II and has seen many of his mutant brethren similarly mistreated. Acting as the leader of the mutant resistance, Magneto has a fair motivation of freedom. Nonetheless, he is a murderer of innocents and has become, by far, the most prominent antagonist in this series.
36. Elle Driver Kill Bill Series
Elle Driver is a real cow...to say it nicely. She clearly kills for sadistic pleasure throughout the second Kill Bill film. In the first installment, she even tries to convince Bill to kill our protagonist Beatrix in an unfair and undignified manner - while she is unconscious in hospital. She has a particular grudge against protagonist Beatrix for receiving more of Bills affection than her, and this adds to her personal conflict with the hero. She has no redeeming qualities as a character aside from being an expert assassin, and is definitely a villain you would hope never to meet in real life.