I don't typically like RPG's, but this is converting me.
The graphics: If you buy it and don't like it, you might just be getting bored with video games altogether.
They're excellent. Not completely brilliant upon first impression compared to other games like Oblivion (IMHO), but once you get into Fable II you realize that, compared to a game like Oblivion, although the graphics are nothing new, the detail to the maps is eventually exasperating.
Bugs:
Not many that I've seen yet, but there are a few. Top of the list: the captions that appear giving you pertinent/relevant information often disappear before you can read what they say. I've even tried to "speed read". Another (arguable) bug is that when you use weapons or spells, they often don't hit the enemy you're targeting. Lastly, when battling numerous enemies, it gets a little too chaotic to tell who you're aiming for.
Overall:
Complaints aside, this game is every bit worth the money and also the book. Not being an RPG-er, I bought it because I love games, popped it in, and after about 30 minutes found myself getting immersed in what I think is a modern masterpiece. I can appreciate the kind of work that went into building a game like this.
Bottom line:
This is a masterpiece. If you buy it don't like it, you might just be getting bored with video games altogether.