Why should we hire you?

This is a pertinent and slightly offensive question. In most cases, this is a trap question meant to reveal your reaction to criticism. If it comes at the beginning of the interview, then you should consider it as a misleading formulation of the question,What's your experience?.

If it comes at the end of the interview, then it is quite obvious that the interviewer knows very well why the company should hire you, therefore, he doesn't expect to hear a strong argument based on your resume or experience. In this case, stay calm and positive and mention why you like this company, why you want to work in this company, and what you know about it. Showing your interest (for example, showing that you've researched the company and visited their website) should be flattering for the interviewer, who can then quickly pass to the next question.