You might enjoy Deus Ex: Human Revolution, one of my favorite games. It is an FPS/RPG and has a very interesting story, it's set in 2027 and it's all about the morality of cybernetic enhancement on Humans. You might find it especially enjoyable because - excluding the boss battles - you don't have to kill anyone. It's all about choice. Also, I believe there is a patch which allows you to win the boss battles without killing them either. You can play the whole game stealthily if you want.
The fact that a believer is happier than a skeptic is no more to the point than that a drunken man is happier than a sober one. ~ George Bernard Shaw