We have stayed at 4 deluxes, Poly, GF, Contemporary and YC. In order of our preference:
1. Poly (our first love, watching fireworks from the beach, directly across from MK, monorail, laid back atmosphere etc., new rooms are awesome)
2. Contemporary (walking distance to MK, Grand Canyon concourse, monorail etc.)
3. GF (first stop is MK on the monorail, prestige, elegant feel)
4. YC (location to Epcot and MGM can't be beat)
Our complaint to YC was the food/snack issue, where do you get a light breakfast or late night snack? The bakery thing at the BC was too crowded in the morning. Captain Cook's at the Poly and Food and Fun Center at CR are open 24/7 for a snack. GF felt a bit stuffy at times I'm sure because we are used to the relaxed atmosphere at the Poly.
Our recent 8/9-8/16 vacation was to be at the Contemporary but 3 weeks before we were to leave, we changed the reservation to the Poly because my cousin was planning on proposing and thought the beach at the Poly would be the best place to do it. He ended up proposing during Wishes at the MK in the Plaza Rose Garden. (BTW, she said yes.)