Sample excellent response:
I sincerely believe that I'm the best person for the job. I realize that there are many other college students who have the ability to do this job. I also have that ability. But I also bring an additional quality that makes me the very best person for the job -- my attitude for excellence. Not just giving lip service to excellence, but putting every part of myself into achieving it. In college and at my previous jobs, I have consistently reached for becoming the very best I can become. I think my leadership awards from my college, and my management positions result from possessing the qualities you're looking for in an employee.
See also this page of our Job Interviewing Tutorial.