Quick tips
Be prepared for any question under the sun. The real world will throw up completely unexpected challenges, and whether you will be able to face them then could be determined by your answers now.
When asked personal questions, answer in a mature manner. Answers like 'this is personal stuff and since I don't know you personally, I cannot answer this question' will not go down too well.
Remember, every interviewer asks questions with a sense of purpose. Make sure you answer every question sincerely.