My recommendation would be either BCV or BWV (personal preference is BWV). The reason is because of the park hours. Usually in September/October, the park hours are reduced and if you want to have some "atmosphere" in the evenings, the Boardwalk area is the place to be. The "street" performers will still be there and it's just a wonderful location. (this was a tip from Disney when I was planning my wedding).
While the other resorts are wonderful, besides the resort, there isn't much to do after the parks close. But, in the Boardwalk area, there's all kinds of stuff to do and see.
The only caution I would give is that October is the food and wine festival at epcot and rooms at all the epcot resorts fill quickly.