I'm always a sucker for a bad guy who decides to do something good. I loved playing Shadowrun because we got to be criminals as well as degenerates and anti-heroes. A good bad guy is hard to find.
Most movies have them as completely evil, or completely bumbling, ordering knee caps taken out by incompetent underlings who fall down stairs. That's always good comedy relief, but how good is the good guy if he doesn't have a good bad guy?
Superheroes tend to bug me because everything is white and black, good and evil. There's no middle ground with Superman or Spiderman. Where is the moral dilemma? What makes the good guy really good if you can't see him/her stretch her mind and actually think about what they are doing?
Dr. Horrible is one of my favorite bad guys. Dr. Horrible's Sing Along Blog follows his rise to evildom from his point of view. To him, he is saving the world, keeping it from the evil that is society. The good guy in the movie, Captain Hammer, feels like he is the bad guy. He has a white/black point of view, and is seriously shallow, and does what a hero does - kicks the crap out of the bad guy and steals his girl.
Bad guys are just like everyone else. They have a skill, they use it. The Transporter is a bad guy, but he kicks the really bad guys' butts. Jet Li in Romeo Must Die is a bad guy, but he does it to revenge his brother's murder. Bad guys have motives, lives, and feelings just like every other character. Stories wouldn't be as good without a bad guy, happy endings wouldn't happen without a bad guy.
So let's give a cheer to the bad guys that make it all entertaining.