TIPS:This question is not requesting that you attack the character of your fellow candidates or compare yourself negatively to them. It is shorthand for "why should we hire you" or "Why are you special?" Again think about the person specification and make sure you know what sort of academic they are looking for. Talor your own responses to that as much as possible.
Make sure you give examples from your own history to support your assertions. So for example, if it is an open coming department looking for a high flying rsearcher to boost their reputation, emphasize your role in this. If there is anything you do that makes you stand out, for example scalar area of experience, mention that here, too.