I have never played Fable, or Fallout. Do I need to play the originals now and work my way up, or can I jump in now and be okay?

I'm trying to get into more games like this. I have played a lot of FPS over my gaming career, but I haven't really been satisfied with the non-multiplayer aspects of most of them. I just enjoy playing multiplayer with others. I guess I'm looking for more RPG type games or any other type you could suggest. Any ideas?

edit I also have an old PS2 and was thinking I should probably pick up Shadow of the Colossus as well to get things started. Good idea?