I've stayed at four.
In 1981, I stayed at Club Lake Villas, which was part of the Disney convention center that became Disney Institute. Terrific L-shaped rooms, which separated the bedroom from the public area. I was crushed because I couldn't get a reservation at the Contemporary Resort for the time I was visiting!
In 2003, I stayed at Yacht Club, then Coronado Springs. In 2004, Pop Century. Enjoyed all of the resorts for different reasons! Very good service at all of them, as well.
Hoping to squeeze time and money for a Holiday 2006 visit, probably at PC again.