You knew where this list was headed, didn't you? Khan Noonien Singh is the ultimate Star Trek baddie, hands down. No wonder fans got so excited when we heard the first rumors that he might play a shadowy role in this year's Star Trek Into Darkness. We met the genetically modified superman in 1967's "Space Seed" episode, where he was discovered and defrosted by the Enterprise crew 300 years after his reign as a sorta-benevolent despot on Earth. Of course, that was just the beginning. He returned 15 years later for 1982's Star Trek II: The Wrath of Khan, widely recognized as the franchise's greatest film. Over the course of the two stories, Khan came into his own as a most worthy adversary – a tragic hero of sorts, undone by his own desperate need for revenge. He's also entered Internet legend as the subject of an all-time great meme. No other Star Trek villain comes close.