There are several work ethics and each of them is as important as the other. However, if the interview poses a question about which work ethic would be considered the most important by; you can say that you consider self responsibility and hard working (dedication) to the most important. Self responsibility is most important because it is one of the core work ethics. Also, if a person has self responsibility and works hard to achieve goals, it is beneficial to the company as well as the person, simply because the company would not have to spend resources keeping an eye on the person as the employee would work well.