Why do you want to be a doctor?
Although the most common question, it is definitely the most important question. Do not just say you want to help people. Give specific examples, scenarios that have shaped you and made you choose a career in medicine.
Do not be afraid to show your feelings and emotions, show that determination, also do not be afraid to divulge incidences in your life that shaped you and are dear to you, i.e. situation that moved you or the passing of a close family member (not grandparent, everyone goes through this one and will not set you apart from other applicants) or friend. This answer MUST be an honest one and should come from the heart. Interviewers are looking for honesty in this question and will be able to tell by your body language and tone of voice. Only an honest answer can give you that body language and tone of voice that you need get through to the interviewer on a deeper level.