I once had an interviewer ask me my greatest weakness, stop me before I started to speak, and added "don't even try to give me an strength dressed up as a weakness because I'll keep rejecting your answer until you give me one I like." Upon hearing my response, he asked me what I was doing to combat that weakness. Upon hearing that response, he asked me how progress was and to project how long it would be before it was no longer a weakness. That line of questioning was far more effective and a whole lot more fun.