I've stayed at the BC and OKW. Although when I stayed at the BC it was in a normal room and not a DVC unit. My family and I loved it! It was so close to Epcot and Hollywood Studios. I have heard the villas are on the smaller side though. I recently stayed at OKW and LOVED it! the rooms were huge and we always had great success with the bus transportation (expect to DTD when the boats aren't running, then it was not good) We are planning a trip to SSR in the summer so I can't speak about that. So it basically comes down to whether you prefer size or location, imo. (Oh, and OKW is USUALLY cheaper) As well as what's available.
If I really had to pick between those three though... I think I would go with the BC, but it would be a really hard decision.