"What are your long term goals?"
This question is asked to see how serious a candidate is about his or her career. Some people might not know their long term goals, and some people might have long term goals of becoming rich and retiring early. Those are incorrect answers for this question. The type of answer you want to give is an ambitious answer that shows you really love your career. A good interviewer will read between the lines and find out if a person is going to be a hard worker or just a mediocre one. Being descriptive and shooting for a big goal is something interviewers want to hear.
Short Answer
"I would like to become a director or higher. This might be a little ambitious, but I know I'm smart, and I'm willing to work hard."
"After a successful career, I would love to write a book on office efficiency. I think working smart is important and I have many ideas. So after gaining more experience, I'm going to try to write a book."
"I've always loved to teach. I like to grow newer employees and help co-workers where ever I can. So in the future, I would love to be an instructor."
"I want to become a valued employee of a company. I want to make a difference and I'm willing to work hard to achieve this goal. I don't want a regular career, I want a special career that I can be proud of."
Long Answer
"My long term goal is to become a partner for a consulting firm. I know the hard work involved in achieving this goal, and I know that many people fail to become a partner. That's not going to stop me from working hard, learning everything I can, and contributing to a company where I'll become a valuable asset. I know it's not a guarantee, but becoming a partner is a long term goal of mine, and I am going to work towards this goal throughout my career."
This example shows a candidate with a big goal. This person identifies the difficulty of the goal and shows the steps required to achieve this goal. Despite the difficulty, this candidate shows he or she will not get discouraged with difficult situations and will never give up. It is a short answer that goes a long way.