For us, it depends on the mood of the moment.
We stayed at Music during our Christmas trip (and on several occasions in the past). The newly refurbished rooms were great. The kids loved the "idea" of being able to participate in the extra activities during the day and the movie at the pool at night (but never actually followed through and did any of them!!). The food court was very clean and never completely full, despite it being Christmas. Lines moved quickly. CMs were extremely friendly, engaging dd in an impromptu band outside the gift shop on Christmas morning. We were in Country Fair Building 6, which was a huge disappointment when we first saw it on the map (LOOOOOOOONG walk from the overflowing with luggage car). However, we ended up LOVING the location because it was so quiet and removed from the rest of the hub-bub. From an angle, we could see part of the quiet pool from our window. We also looked out on a little courtyard with picnic tables. Very nice. Wait for buses was never, ever long -- going either direction. We sometimes shared with the other resorts but not always. It seemed to have more to do with the time of the day (scheduling) than with how busy the buses were, as we occasionally had a bus nearly to ourselves but didn't go to another resort.
In July, we spent a night in Sports (and have stayed here on a couple of other occasions, too). Our room in Building 9 of the Home Run Hotel was one of the first that had been refurbished. We were so impressed during this brief stay that we decided to downgrade part of our Christmas trip to a Value and save some money in the process! From our room, we had a partial view of the Grand Slam Pool. While our room was in the back of the resort, we were able to park quite close by. Since we were only here for a night, we didn't mind the walk to the front of the resort. On other fairly recent trips, we have stayed in the Center Court section. The walk seemed about the same, without the added bonus of being able to see a pool. Again, we were favorably impressed with the food court, overall cleanliness throughout the resort, and CM friendliness -- all of which had NOT impressed us during stays in the past.
Since the kids have never visited Pop, that is where they have chose to take us during our March/April trip. Dh and I have stayed there for a night here and there before checking into our deluxe digs. We have always been impressed. The theming of Pop seems to appeal more to adults than do the All Stars. Our favorite room at Pop was in Building A in the 50s section, facing the Bowling Pin pool. The location was excellent, just a short walk to the front of the main building. I've never eaten at Pop, but the kids are excited by the prospect of tie-dyed cheese cake and Coke slushies. It doesn't take much to please them. I have read on these boards that Pop really needs refurbishing. Sports and Music definitely did and now seem so much nicer with new paint and furnishing. Hopefully, Disney will follow suit with Pop soon.
I really don't think you can go wrong with any of the Disney resorts. Just choose which one you can best afford and appeals most to you. Yes, you can have a bad experience at any of them (just as you could at any off-site hotel). But you're far more likely to have a truly magical visit...especially if you begin with a positive attitude.
