The Contemporary!! Magic Kingdom view can't be beat. We spent more time on our balcony than in the parks the trip we stayed at the Contemporary tower (May 2003). From our balcony we could see the MK (fireworks!), Poly, GF, TTC, all the boats in the Seven Seas Lagoon, and with binoculars we saw the monorails in the TTC and MK stations and people walking around in Tomorrowland. I saw monorails switching onto the garage beam at night. And it's nice to have everything in one building, unlike the Polynesian..
I really disliked the Polynesian. The grounds are beautiful and the GCH is nice, but the rooms are very.. brown and yuck. The place seems really run down. My cousin stayed there in August (us in December) and she felt the same way, and they were even concierge. I realize that a lot of people love the Poly, this is just my opinion.
We've also stayed at the Dolphin.. I don't know if this counts as a deluxe resort or not. We found it to be very noisy and hard to get around.