The questions that FuturePittMed mentioned (Why medicine? Why this med school?) will almost certainly be asked at every school. His/her advice to look at the interview feedback for each school is also good; many of those same questions tend to be asked of future applicants. Other common questions that you should be prepared to answer include the following:
Tell me about yourself.
What is your biggest weakness?
What questions do you have for me?
Tell me about your research (if you've done any).
Tell me about X and Y ECs.
What do you like to do in your spare time?
How would you add to the diversity of our school?
You may also get some more general questions about ethics or your readiness for coping with the demands of med school.
One of the most amazing things to me when I interviewed as a Southerner at Northern schools is that I constantly was asked how I would deal with the winters. I was amazed by that question for two reasons: I wouldn't not attend a school just because of the colder climate, and it's not like the fact that it gets cold up north was a big surprise to me! I have to wonder if you Northerners who interview down South get asked how you'll deal with our hot, humid summers.
Hope this helps, and best of luck.
🙂