"Five years from now, I would love to see myself growing into a more prominent leadership role within your organization. My career interests align very nicely with your company's growth plan, which helps me to see a great long-term fit here."

Even though it is impossible to know where you will be in five years, assure the interviewer that, given all possible circumstances, you hope to see yourself in a prosperous career with them. The way to do this is to show them that you have thoroughly thought through your decision to pursue this position, see it as an opportunity, and are emotionally invested. Show them that you see this as an ideal fit and would love to work with them. As Steve Jobs said, "The only way to do great work is to love what you do." So when answering this question, show them you would love to work with them and would do great work with them, given the chance.