~Eliminated Villains~
-Ash/Angela from Black Butler
-Sugou Nobuyuki/Fairy King Oberon from Sword Art Online
-Sloth from Fullmetal Alchemist Brotherhood
-Frieza from Dragon Ball Z
-Kira Kousuke from Btooom
-Sousuke Aizen from Bleach
-Donquixote Doflamingo from One Piece
-Johan Liebert from Monster
-Myotismon from Digimon Adventure
-Love Machine from Summer Wars
-Darcia the III from Wolf's Rain
-Schneizel El Britannia from Code Geass/R2
-Shinobu Sensui from Yu Yu Hakusho
-Acnologia from Fairy Tail
-The Millennium Earl from D. Gray-Man
-Crocodile from One Piece
-Raynare from High School DxD
-Asura from Soul Eater
-Sabrac from Shakugan No Shana 2/Final
-Brain/Zero from Fairy Tail
-Medusa Gorgon from Soul Eater

D: Izaya's a great villain! Just because he doesn't have superhuman strength doesn't mean he's bad! From what the anime and manga show, Mikado simply happens to go to Ikebukuro, and within a day or two, Izaya's already gathering/gathered info about him. As quoted from AnimeAvarice when I asked who's bad side she'd rather get on (Izaya or Shizuo) she said...

"Shizuo's bad side. At least you can SEE him coming and he's straightforward. All you need is some time to run. Izaya..... -shudder- He'd probably send a missile launcher to the city while you're sleeping, bomb the entire city, send in spies to make sure your dead, and then sit back and laugh."

Brains is better than brawn in Izaya's case.