Just a word to the wise: If you asked which resort was good for a 5 year old, a 50 year old, an 80 year old, a dead dog, a paper clip or Jesus Christ Himself, the winner would be the Poly.
The Poly wins every contest it is in around here. It IS a great hotel and would suit your needs well! I'm not slamming it; it's great. But it doesn't matter what you put it up against, or for what reason, the Poly always wins.
I voted for the Beach Club because it never gets enough votes and has the best pool for kids, IMO. But if the Magic Kingdom is where you'll be spending most of your time, then a monorail resort is a good choice (Poly.)