Hello, Ariana!
My, you've selected such wonderful resorts at Walt Disney World; no wonder you are stuck in your decision!
If I were headed to WDW next May/June, I would probably choose Disney's Polynesian Resort. While I may be partial to
Disney's Polynesian Resort because it was where we stayed on our very first visit to WDW, it's also just a great property. There are some fantastic dining options there and the Nanea Volcano Pool is really spectacular.
Of course, the other resorts have great benefits, too, including excellent dining as well as fantastic access to the monorail line. In addition,
Disney's Contemporary Resort has the added bonus of really excellent proximity to Magic Kingdom...you can even walk between the resort and the park in about 10 minutes.
On the other hand, if you're looking for a resort which includes a fabulous spa,
Disney's Grand Floridian Resort & Spa may be just the spot for you. The Spa is scheduled to reopen after extensive refurbishments on December 5th. For a menu of offerings at the Spa, check out relaxedyet.com. When the spa is ready to release details of its offerings, you'll be able to find them there.
Send more questions as you think of them; I'd love to help you plan your trip to WDW!