1) The Spiral King, Lord Genome (Tengen Toppa Gurren Lagann)
2) The Boss (Metal Gear Solid 3)
3) Tendou Kodzune (Tokyo Majin Gakuen Kenpuchou)
4) Zaraki Kenpachi (Bleach)
5) Knives (Trigun)
6) Mid-Boss (Disgaea)
7) Dracula (Castlevania series)
8) Baphomet (Ragnarok Online)
9) Possessed Kafra (Ragnarok Battle Offline)
10) Ridley (Metroid series)
Man, why do I only know about awesome villains that nobody else has heard of? Nobody's gonna renominate these choices.