BioWare created a monster.
Mass Effect is a series with unlimited potential, granted, it's not the first RPG where your decisions affect the world, but it plays with the notion that everything you does will come back to bite you in the ass sooner or later, and it did, for most of the game, characters wouldn't forget your kindness (or lack of), sometimes I even found myself asking who the hell was that person sending me an e-mail thanking me for saving them. Feedback, all the time, you could influence your companions through your own personality, handle people and situations in so many different ways I wouldn't doubt that there isn't a single