Tyranny is really good, and deeply uncomfortable. It's a bit short, but has four major plotlines so quite replayable. One of them has you helping a complete monster however, which I don't think I can bring myself to do.

Noah Caldwell-Gervais has a good video on the game: http://www.youtube.com/watch?v=DaqqCbmhqVI (spoilers)

"It may have a fantastical frame with Beastwomen and magical swords, but the fundamental basis of the game is exploring the psychology of evil. In the process of making that exploration interactive the game hammers home things that a dry article in an academic journal might not. You are not reading about the Milgram experiments or hearing about them in a class, you've got your hands on the dial of a sword & sorcery version of the real deal. With characters and authority continually asking you to apply just a little more voltage."