3. Ultron (Marvel Cinematic Universe)
Ultron was always going to be a cool villain. Ever since the Comic Con announcement that the Avengers sequel would be subtitled Age of Ultron, we've imagined how awesome he will be (even if we were a little disappointed that Thanos wasn't going to be the main villain). But since the excellent and very creepy James Spader was unexpectedly cast in the titular role as the villainous robot, excitement has gone in to overdrive. The star of Boston Legal and The Practice is an absolutely inspired choice and will undoubtedly make a perfect Ultron. Ultron has had many incarnations in the comics, but generally possesses a genius-level artificial intellect, superhuman levels of strength, speed, stamina, durability and reflexes, the power of flight and the ability to fire powerful blasts of concussive energy from its hands and eyes. Going by the glimpses we've had of him, he will look fantastic too.