DH and I have this goal as well. Together we have stayed at:
GF, Polynesian, Coronado Springs and Animal Kingdom Lodge.
I've also stayed at All Star Music and Caribbean Beach.
So that leaves (for me) All Star Sports and Movies, Port Orleans FQ and Riverside, Contemporary, Wilderness Lodge, Boardwalk Inn, Yacht Club and Beach Club and the villas (but I don't think you HAVE to count the villas as separate resorts, do you?) and I Old Key West and Fort Wilderness. I probably won't count Swan and Dolphin either since they're not owned by Disney.
And you know, I think meeting this goal will NOT be easy because there are some resorts that I just love, like the GF and Polynesian and it's going to be hard to choose Port Orleans over the Polynesian, you know??
But we are planning a couple of trips - October 2003 to Port Orleans Riverside and August 2004 to the Contemporary or Beach Club (or maybe we'll split our stay then if we go for two weeks).
I think it's a fun goal to have, though, don't you?!?