What is the most difficult question have you ever heard in management position interview?

As a manager how do you handle interference in your department?

"Why should I hire you over the other candidates I have interviewed?"  This is usually the question that stumps most interview candidates. They have not analyzed the job description or the available information on the prospective employer, and cannot quantify how their qualifications match that job description for that employer.  Candidates lose the opportunity if they cannot answer this important question.  If you don't know yourself, how can you convince the hiring manager?