"What would you say is your greatest weakness?"
Well, I would have to say that I can be overly empathetic. I tend to be able to see and understand both or all sides of a situation, so it can be difficult for me to choose sides. When in doubt, I frequently take the side of the underdog. This can sometimes lead to devil's advocate situations, and can be downright unpopular.
Honestly, I think this is one of the silliest job interview questions ever. That and "Where do you see yourself in 5 (10) years?"
