An excellent overview of philosophical/ethical systems. If only I had this book earlier when I started reading philosophy, I'd have saved a lot of time. Go for the iTunes U version if you'd like! 
 Starts off with a brief overview of ethical systems - utilitarianism, libertarianism, Kant's categorial imperative, Rawlsian justice, and then works through case examples - affirmative action, euthanasia, etc. Very clear and thorough arguments, for and against. If Sandel has a bias for one over the other, he hides it very well.