CareerJournal.Com offers some great tips on responding to “extreme” questions in an interview (e.g. questions like: “What would your last manager say is your biggest shortcoming?”)
The author emphasizes the importance of being prepared for these questions but highly discourages text book answers like “I work too hard.” He suggests that you should come up in advance with three or more career success stories and two or more stories that had less than favorable outcomes but were learning experiences. He also provides some good language for connecting the interviewer’s question to you answer.
There is a link in the article to some challenging questions you might face. For more materials on interviewing, I have an article of my own which includes more basic interviewing questions.