Hi Kanani:
There is so much to do at Disney World, which includes four theme Parks, two water Parks, and a "downtown" shopping and entertainment district, that it's hard to be "perfectly" centrally located. Most Resorts may be close to one or two Parks, but further away from the other Parks. So if you plan to visit all four theme Parks, you'll likely have a bit of a commute to one or two of those Parks no matter where you stay. But, you can always take advantage of
Disney's complimentary transportation to and from your Resort and Parks.
I think the best Resorts for ease of transportation are located in the
Boardwalk area. Specifically, I would look at the
Beach or
Yacht Club Resorts. Not only are these Resorts centrally located near that entertainment and restaurants of the Boardwalk area, but they are a quick walk away from Epcot, and long walk or short boat ride away from Hollywood Studios. The
Boardwalk Inn is also located in the same area. Another option is a Resort on the monorail line, These Resorts include the
Contemporary Resort, the
Polynesian Resort, or
Grand Floridian Resort and Spa.
Enjoy your vacation.