What? Nobody mentioned Khan yet?
Khan Noonien Singh was an interesting character. In The Space Seed, he was the product of a eugenics war. He was bred to be a leader. According to the backstory:
Wiki said:
Khan had been both the most successful conqueror and the most benign ruler of the group, ruling more than a quarter of the Earth's area across
Asia to the
Middle East from 1992 to 1996 with a firm but generally peaceful hand until he was deposed.
After he and his group was placed (or marooned) on Ceti Alpha V., he blamed Kirk for not checking back on them. I would say, that was a legitimate gripe.
While he had all his appendages, he had been transformed into Ahab and Kirk was his White Whale. After he escaped the planet, he did not slaughter the crew of the USS Reliant, but stranded them on the planet. He did torture and kill the scientists on the Space Station on Regula I because they stood in the way of his goal, Genesis and ultimately Kirk.
As I have previously stated, I'm a big fan of Japanese Anime. One of the reasons is that in many of the stories, the "villain" is being driven by conflicting goals and they take the time to present the view from the alternate side. Big, complex stories.
Khan was doing only what Khan COULD do, it could be argued that he was mad and had no free will. This is MUCH different than The Joker's madness which is driven by his desire for mayhem.