Mass Effect and The Witcher are the two best RPG trilogies in existence if you ask me. They both have a good combat system, an interesting story, fleshed-out characters and allow you to make your own moral choices throughout the story and what's cool is that you can carry those choices over to the second and third game respectively. I was underwhelmed by the ending of Mass Effect 3, but the journey it took to get there was still incredible.