I've heard some people rave about Fable II and some people insist that the first Fable is the best.
I've been playing Fable (I don't have II) and I'm thinking "Yeah, this is a pretty good game, but it suffers from first game in a series syndrome, where it's got elements that feel unfinished that were expanded upon in a later game. But yet a few people say THIS game is the best..."
You'd think the sequels would improve on the original, but Fable seems to go in the opposite direction. There's far less legendary weapons to find, less demon doors to open, armour is removed from the game completely the number of spells available is heavily reduced and magic system itself is barely usable. Basically, every spell has five possible levels of potency, and each higher level requires at least a second of time to charge it up, during which time you're completely immobile. When you reach the mid to late game where low level spells are effectively worthless against the various mobs, you've no choice but to take a fuckton of hits if you want to do any sort of respectable amount of damage.
Granted, NPC interaction is somewhat improved, and buying property is so much better in the second game (you don't have to kill the original owners to buy a property and rent is dumped straight into your inventory rather than having to physically go and pick it up every three days) and there's a little bit more to getting married and breeding. Not to mention, the maps are now a respectable size. That's nice and all, but it's rather frustrating how they seemed to only improve the side fluff while the core gameplay got rather gimped.
So yeah, if you do want to play the second, don't expect much of an improvement. It's still a fun game, don't get me wrong, just not quite as good as the original.