Laser Man from Mega Man Battle Network 4 is one of my favorite villains. He has a super armor, so he never flinches when attacked by weapons like Vulcan and Air Hockey. His primary attack is Cross Laser, which strikes whatever panel that you're standing on. It rarely misses. In order to beat him, you have to use plenty of recovery chips and stay alive for as long as possible. Demise from Legend of Zelda: Skyward Sword is my favorite villain, too. He has the perfect looks for a villain, he's the source of all monsters, and he was very hard to beat. GLaDOS from Portal, Bowser from Super Mario, Psycho Mantis from Metal Gear, and Wesker from Resident Evil are also my favorites.