Even though this thread hasn't had a response in a few weeks, I just had to chime in about the Polynesian. I haven't been to the other two but I love the Polynesian.
Access to the monorail and the quietness - if thats a word - of the resort are plus. (stole these from Luau Cove :animwink: )
Also it has a great view of the Magic Kingdom.. Our hotel building was right by the beach, so I could stand on the outside stairwell area and watch the MK fireworks and lights.
And the food at the Ohana Cafe was a plus!
Well of the 3, I've only stayed at the Beach Club. I had a horrible experience and will never say there again! If I had to pick I would say the Polynesian, the themeing and grounds look beautiful, plus you have the view across the Lagoon.