Behavioral interview questions are tough. They make you squirm because the answer isn't written in stone, and you sometimes can't tell what the interviewer is looking for.
Here are some behavioral interview questions (and answers) I've been asked in the past.
1. (For a telemarketing job). Tell us about a time when you had to persuade someone one to buy something. I answered with the time I sold magazine articles to a publication. This apparently wasn't good enough. I didn't get the job.
2. (For a teaching job). Tell us about a time when something went wrong in the classroom (now pretend it hasn't happened, it has happened to all of us). My answer-- I told the committee about my experience with a group of medical secretarial students who were difficult to teach. I explained what I did that didn't work, and why I thought that. Then I further detailed what I learned and what I would do differently. (I did get that job).
3. (For another teaching job) "Tell us about your greatest accomplishment". I said that my greatest accomplishment as a teacher was the students who wrote to me and told me that they learned something. I think they wanted to hear that I had develop some amazing program that changed the world. Perhaps I gave an example that was too low key, or perhaps, I hadn't thought more thoroughly about my accomplishments. I didn't get that job.