We're a Poly family all the way -- we've tried others and spent the time wishing we were there. But I really think it's a matter of personality and if you ask yourself a few questions you'll know where to stay.
<b>Do I want to be closer to the MK or Epcot -- or does that matter at all to me?</b> We've stayed at Epcot resorts and it is very nice to be able to walk there for dinner, but we are such big giant Disney nerds that we love being near the MK. Although since you can walk to the TTC from the Poly, the Poly is good for both MK and Epcot.
<b>Am I renting a car?</b> I personally would never stay at AK Lodge without one -- taking all those buses would kill me.
<b>How much Disney Magic do I really want?</b> Some people want the theme turned up full blast (like us) and some just want a really nice hotel. I would say that the GF and the Yacht and Beach Clubs are a little more polished than the Poly, but not quite as over the top Disney themed. When we go we are

very nerdy about the whole thing.
<b>How much do I really want to spend?</b> My experience (and this is just mine) is that we've found better rates at the Poly, WL, and Boardwalk, the Contemporary, and the Dolphin. They are still expensive, but just not as much as the others.
That said, we are just happiest at the Poly -- who knows why?