Michael Sandel is a popular if not controversial Harvard professor. His course, Justice, has been taken by thousands of Harvard students and is now available entirely free on this site. Criticism I've heard often centers around the idea that it is "philosophy lite" but I personally find it, at minimum entertaining, and I think it can be useful tool for self-examination for most people. If you enjoy questioning the basic assumptions of our lives (but are not a formal student of philosophy) you may enjoy this too.