Hmmm... Going to vote Unova, and whilst the official reason would be because I think it's a nice, varied region that would be really fun to explore, the real reason is because Pokestar Studios. >.> <.< Also my vote is for Unova as it is in BW2, since that means Roxie.

Anyways, just wondering what kind of plot and tone you have in mind for this? Since that would kind of play a big part in whether I'm fully interested or not. ^^;