4. Pac-Man Ghosts
What Makes Them Bad: They're out to give Pac-Man the business.
What Makes Them Cool: If they touch Pac-Man once, it's game over. They come in different colors! They may not have much of an agenda (save for nabbing Pac-Man) but they're some of the most recognizable villains in gaming history. Inky, Blinky, Pinky, and Clyde are pretty tough customers.