What a difficult question!!!
I tend to be drawn to most of them for various reasons, and depending with whom I am vacationing, as well as budget.
If it was just me and DH, then I would probably choose Boardwalk or Grand Floridian. Both are convenient to the parks, and are a little more adult feeling in theme.
If I were there for a quick vacation where convenience was my ultimate goal, and wanted the largest room I could find, I would choose the Contemporary.
If we were going to spend most of our time at MGM and Epcot, and lounging around the pool with DD, then I would definitely choose the Beach or Yacht Club.
If we were going for a good amount of time and MK and Epcot were the focus... and we wanted to feel relaxed at the same time, I would choose the Polynesian.
If we had a rental car and were going in the winter months, I would probably be tempted by the AKL.
If DH was going by himself (yeah, that'll happen!

), then he could stay at the WL.