I can't tell you the best answers to questions, because frankly, I don't know you. I keep all my answers pretty short and simple and above all, I am honest. If I am looking for work-life balance, I'm going to ask about it. No point wasting both our times if the job requires me to work lots of weekends and OT.
Also, keep in mind many answers can be used for multiple questions. For example your answer to “your biggest strength” can also be used for “tell me about a time you succeeded” You just have to think on your feet and tailor your response. It's hard to do, but practice makes perfect. Also, really pay attention to what the interviewer is saying. Always try to find ground you can relate with and if possible, listen > speak. People love to talk about themselves.
Anyway, here are the top 5 questions I've come across while interviewing (both as an interviewer and candidate)
1. Tell me about yourself
2. Why do you want to work here
3. Tell me about a difficult project/work related experience and how you overcame it
4. Why do you want to leave your current job (if applicable) or why you left your current job
5. Do you have any questions?
Questions I always ask to the interviewer:
1. Why is this position open? I want to know if the person quit, got promoted, left department etc.
2. If I were to start tomorrow, what would I be working on?
3. What are the biggest challenges with this position?
4. Why did you choose to join this company?