3. Aldrich Killian (Iron Man 3)
MarvelYes, almost everyone hates Iron Man 3's Mandarin twist, but their hatred of the deception over Ben Kingsley's character has clouded their opinion of Killian, an otherwise excellent villain. Aldrich starts out as a nerdy, socially awkward man who approaches Tony Stark in 1999 about an idea he has for a think tank called AIM. Tony lies to Killian just to get him out of his hair, and this leads to Killian harbouring intense hatred towards Tony for years to come. Years later, after the events of The Avengers, Killian reenters Tony's life as a suave businessman in control of his powerful "think tank", which is really a front for a super soldier army Killian has created. These super soldiers were created by Extremis, a compound that allows people to regrow lost limbs and have super strength. Killian is the mastermind of the Mandarin plot, in which an actor is hired to portray an international terrorist and drive the public to absolute panic. Killian is a brilliant man, both as a technical genius and as a criminal mastermind. The Extremis serum also allows him incredible strength and the ability to breathe fire, making him arguably the second strongest villain behind the Abomination, who is essentially the Hulk (not bad for a skinny businessman!). Even though the Mandarin twist was not well received, Killian's ability to conceive this plot and the way he absolutely thrashes Iron Man in their final confrontation earns him a place in the top 3.