The series is soo dumbed down now it is insulting. I will stand by that the first one was a good game but the rest were massive disappointments. The IP should just be passed on to another studio like Bethesda,Obsidian, or CD Project RED, they actually know how to make RPG's.
It isn't exactly an RPG, though, in my opinion. It falls somewhere in the crevice between Action/Adventure and RPG. I don't think it should be judged as an RPG, nor do I think any game should be judged based on genre, but as an experience, and in my mind, Fable has delivered something unique.
Please note that I agree to some degree that the series could be monumentally better than it currently is, but I think people are too hard on them in general. I never paid much attention to Lionhead or Peter, only bought the games when they came to the Box, and they've satisfied me fairly.