So I like systems that provoke fiction that's not only guided in some way but, more importantly, useful. Or actionable. I haven't really figured out the best word for it.
See, when I'm at the table and it's my turn to say something, Apocalypse World gives me things to say. This requires two things, though: moves and moving pieces. So the moves alone are great but not sufficient, I also need pieces (NPCs, factions, relationships, feelings, details of the fictional environment...) to move. Apocalypse World does a great job in many ways of providing these pieces (I.e., the actionable fiction) through the setup and moves. The Hx questions in the playbooks, more than establishing some number, give players bits and pieces of fiction to work with (again, NPCs, relationships, memories...). Reading a sitch provides reliably actionable fiction. Deep brain scan does. Many of the moves are great at this. Creating Fronts is exactly this. (So are town creation in Dogs and oracles in IAWA; but neither of those games does this as well during actual play, with Dogs' raise and sees requiring it but not providing near as much specific help as AW).
I'm going to point out, too, that I personally could use a little more from AW in the initial setup. "Ask questions like crazy" and "look for where they are vulnerable" are good starts, but more specific questions would, for me, provide more reliably actionable fictional pieces. AW can definitely do this with its default assumption of scarcity, for example, by asking about the various sources of resources, who holds them, and at what price or danger. I mostly point this out because I feel that a more thorough setup could have helped my (greaat) current AW game be even better.
I was thinking about this while reading Monsterhearts, because I think those initial questions will be different for each hack. But also, hacks should make sure that their moves provide good moving pieces/actionable fiction for the game to keep rolling on.