Another vote for either the GF or Yacht Club.
However, unless you plan on spending the majority of your time at the Magic Kingdom, I would go with the Yacht Club.
BC (before kids), my wife and I always stayed at the BW, which is right across from the YC. Without kids, we knew we wouldn't even go to the MK, so there was no reason for us to stay at a monorail resort. By staying at the YC, you will be a short walk to Epcot, and a short boat ride to MGM Studios.
You are a short walk to the BW, so you will have more late night entertainment options then at the GF. You are also a short bus ride or car ride to DTD. The bus ride from the GF to DTD is unbearable.
If it were just my wife and I, would def take the Yacht Club over the GF.