Why do you enjoy working here?
This question shows you have an interest in the person you may be working with. It often also endears you to them, as it shows you as someone interested in the wider culture and in the people you work with. Aside from these benefits, it will give you a good insight into what it is like to work there and how happy employees are. If that person is happy, they will be able to give you 2 or 3 reasons pretty quickly. If they are struggling to answer, it should be taken as a big warning sign!