Badass Villains

[Frisk E. Coyote]

Ooh! Ooh! Vergil from Devil May Cry! The first time you face him, he fights you without ever running! And with only his Katana, I had trouble beating him the first time, due to... noob problems.

Then there's Hisoka of HunterXHunter. A psychotic battle genius who never seems to take things seriously, yet manages to defeat a powerful opponent despite- oh, I don't know, HAVING BOTH ARMS TORN OFF. He's also insanely sadistic, getting aroused at the thought of fighting powerful opponents. Creepy. I LOVE HIM!

For some reason, I find Orochimaru from Naruto to be very badass. The guy just won't die, and I love that he's creepy. He took Naruto in his three-tailed demon fox mode on and survived despite being severely weakened by the need to move to a new body. I could very well be the only Orochimaru fanboy in this forum! ^ ^
There was also Gaara prior to his change of heart and Itachi prior to later revelations of his true intentions. Gaara was the ONLY Gennin who could kill so casually and easily. His emotions were always masked, and he stood still when fighting. Itachi was introduced as a stoic, cold and collected character with an uber powerful "lackey", Kisame. His movements were fast, he barely made any moves that the viewers could see, and he slapped around a bunch of Jonins + Kakashi himself. Also, the Akatsuki coats!!

Father/Paladin Alexander Anderson. Just Alexander Anderson. From Hellsing. HE'S GOT AN IRISH ACCENT!! XD

Aizen Sousuke from Bleach. OMFG. Do I need to say more about that guy?

Lord Voldemort. From Harry Potter. In my honest opinion, anyone who's so feared his name was made a taboo, and is capable of killing ANYONE (save for the boy who lived himself) by waving a stick and spouting random gibberish and Latin is badass.