When it comes to top hires, the questions people ask tell you far more than the answers they give.
I have found that the smartest, most agile and innovative people are those who ask a lot of questions. I pay careful attention to the quality of the questions job candidates ask, the way they ask them and listen to the answers, and then construct follow-up questions. This process tells me if candidates are good learners, and gives me an idea of how they navigate the unknown.
It also tells me a lot about what's important to my interviewees. For example, if someone asks me about technology, she's likely a person who thinks most about the product and innovation. If the first questions she asks are about vacation policies, that's also very telling.