The first game was my first leap into RPGs and it did so much more than any other at the time. While most just had a story of "he bad, you good, go kill!" and then you went into some caves like the upteen-millionth Deathtrap Dungeon repeat, Fable introduced so many more things like moral choices, housing, marriage and a very interesting way of learning skills and levelling up. It was good, but my problem was that it ended, and I hate endings in an RPG - the end should be when I choose it to end, not when the final antagonist is killed. What did he do 'til the sequel, huff paint for a few years?
Fable 2 was my favourite with its amazing combat design, customisation, dialogue, professions (my favourite thing), voice actor choice, quests, marriage, children, housing, amassing wealth and so many more reasons to stay with the previous generation consoles. It got everything from the original Fable right then dolloped even more content into that game.
But then Fable 3 came and my God how I hated this one. I just didn't like how poorly told the story was, and how much emphasis there was on the gold trail. The 'end-game' was just a rush to get gold, and I didn't know there was a time limit. So everybody died because of something I overlooked. As you can likely tell, I wasn't very happy and still to this day I'm enraged.
Fable has so much promise but the lead designer wants to put in too much stuff, and ends up with none. What he tries to do new often turns out mediocre, not realising that it will naturally develop over time with more sequels. When he realises this, we might see a real Fable game.
Just my two pence.