Which ethical theory (or combination thereof)

Which ethical theory (or combination thereof) do you think is best? Discuss this question in relation to 3 of the following topics: (a) the stockholder vs. stakeholder theory debate (b) work and family issues (c) affirmative action (d) business and the environment (e) advertising ethics. (Note: Ethical theories are those comprehensive theories such as utilitarianism, contract theory, deontology, virtue ethics, or variations within each. I suppose egoism, relativism, and others count too.)