The characters that aren't quite there upstairs.
A brief look at the villains from your favourite books and films will reveal some common personality traits; they're all a few sandwiches short of a picnic. This is of course true of video games too, with many antagonists - who are more often than not found in the form of boss battles incidentally - displaying qualities that would suggest they're not quite with it upstairs. Here then, are the ten most psychotic characters that have appeared in video games.
Dr. Ivo (Eggman) Robotnik – Sonic the Hedgehog series
Sonic's arch nemesis might have a PHD and an IQ of 300, but there's no denying that he has some serious mental problems. Kidnapping bunnies, birds and other cute mammals and turning them into fuel for robotic enemies, an obsession with taking over the world, and a maniacal laugh that could be described as anything but sane. What's crazier than all this is the fact that even with his vast intellect and knowledge of science and robotics, he's still unable to kill a single blue hedgehog. He really must be crazy if he thinks doing the whole thing for a fourth time in Sonic's upcoming return to 2D is going to be any different. Give it a rest already Eggman.
Sander Cohen - Bioshock
The fall of Andrew Ryan's great underwater city Rapture would be enough to send any of its citizens a bit mad, but some took it considerably worse than others. Sander Cohen was once a respectable poet, sculptor and playwright, a man of many talents who also reigned over Rapture's Fort Frolic. When the city descended into chaos, however, Cohen became sadistically impassive to the death and suffering of others. When the player first meets him, he has plastered his disciple Kyle Fitzpatrick to a piano rigged with explosives. It's certainly an interesting introduction, and the explosion that follows is a clear indication of just how kooky the fallen artist has become.