Fable III is the best of the series by far, but it has a few problems.
Your brother is king, and, well... he's not the kindest ruler. You'll be forced to make some interesting choices early on before you leave the palace.
Now, the conversations in Fable III are deeper, but more shallow... they are deeper because when you talk to somebody the camera now focuses on them (oh, plus you can actually TALK to an individual instead of using expressions on a crowd), and your character talks in this one.
The conversations have lost something, though, because you can't really pick which expressions you'll be able to use. It just randomly selects some. Hopefully Fable IV will combine the good of Fable III's conversations with something like Fable II's expression wheel.
The combat in this game stays pretty much the same as the second, though you can now combine two spells. That's right, you can now shoot electric fire at enemies. Speaking of combat, I should talk about the weapons. They evolve based on your character's actions. For example, my character was killing a lot of Hallow Men with his pistol, so the handle of it slowly became made of bone.
The weapons also get bigger as you level them up. Leveling up is now a menuless affair, instead using "gates" to represent how far you are in the game. The gates control the abilities you can unlock. The farther you are in the game, the more gates are unlocked, and the more abilities you can get.
Instead of experience points, you now have Guild Seals. They're good for any type of skills, so you can use them for melee abilities, ranged, magic, or the assorted social ones. Skills are gained by opening chests. Chests require certain amounts of Guild Seals.
Now, if anybody is reading this review, you might be wondering about the story. Well, I can't say how it will be for you, but it's the best story in the Fable series so far in my opinion. You're probably also wondering about being king. Well, it sucks. Not in the none-fun game-killing way, in the test-your-morals way. You can be a tyrant but help the people in the long run, or be a saint but hurt the people in the long run.
As every Fable game has asked, what will you choose?