If you’re applying for jobs or will in the future, go read this Lifehacker article, The Interview Question That’s Always Asked (and How to Nail It) by Jefferson McDowell, now.
You should memorize and practice these responses.
In addition, before the interview, review what’s important to you. What do you need to be fulfilled in a position? Autonomy? A team atmosphere? A place to grow with potential for internal advancement? Scheduled feedback? The opportunity to continue learning? Mentors? There are no right or wrong answers. The easiest way to figure out your priorities are to think about why you are leaving your current position. Or if you’re a new graduate, what you loved or hated about your pre-professional jobs.
Now look at those priorities and match them up with the job description and what you know from your research about the company.
Is there a way to convey your priorities while also, as the article points out, meeting the needs of the organization? The more prepared you are for your interview, the more you will appear as a strong candidate and increase your chances of being hired.