The guys at Jobacle think they know. "Fictional bosses. They are often even more dreadful then their real-life counterparts. They can utter the words ‘You’re Fired!’ on a whim, cause in the fake world, wrongful termination lawsuits don’t exist."
Get the Worst Boss List here. (pdf)
You'll find dreadful bosses such as Captain Kirk, Keyser Soze, and Willy Wonka.