I would say anywhere at the Polynesian is going to be very nice. The standard rooms are all the same once inside.
I have stayed in 4 or 5 different Garden View rooms and 2 different club level rooms. Every experience was fantastic. The only time I've made a particular request was when I was paying rack rate for Lagoon View club level and wanted to be sure I had either a patio (1st floor) or balcony (3d floor).
Twice we have been assigned garden view rooms in Raratonga and this is a really great location. It is right beside the Great Ceremonial House, and therefore the monorail, the shops and the restaurants. It is also very close to the parking lot (if you're going to have a car), the laundry room and the Kids' Club. It's a great location.
I've also been in Tahiti bldg. and loved it. It's a larger longhouse and newer, with slightly bigger room/bathroom/hallway.
A LOT of people request Samoa. It's between the two pools and pretty close to the beach.
I've also been in Rapa Nui. All my experiences have been good!
I would recommend breakfast at Kona Cafe for sure.
Walk over to the GF along the walkway that connects the two resorts.
Watch Wishes from the beach or the boat dock at the Polynesian, or your balcony if possible!
Walk the grounds of the resort in the evening! It's so gorgeous with the music and the tiki torches
Take advantage of the walkway between the Ticket and Transportation Center and the Poly when going to and from Epcot.
Have a great time