So far I have stayed in 9, 7, 3, and 4, and none of them were a horrible walk to the main building. Out of those, 9 has probably been my favorite, as it was the closest to the end of the lobby building with the food court and transportation. 4 was nice because of the lake view. I always book standard as well.
There are standard rooms in every building, so you can request 60s if you want (closest to lobby and will also be close to Skyliner). None of the buildings are really that far. 2 & 7 would be the only buildings I'd be slightly disappointed to be in. We liked being in 9 because it's close to the buses from the parking lot side. But it will be farther from the Skyliner.
If you stay in 50's 60's or 70's, all are pretty close to the main building. My preference is 60's lakeview. SO SERENE!!!!!! Just beautiful. And its not a far walk. I find 50's lakeview a tad further. I'd pick 60's, then 70's, lastly 50's.
I always tell them at check-in that I would like to be as close as possible to the main building. Paying extra for preferred rooms gets you closer also. Last September I forgot to ask and I ended up as far away as you could get from the main building. I think it was the 80's building (with Roger Rabbit).
We were in the 90's section with the Pac-Man theme. We were close to the parking lot and just a short walk to the bus stops. It was a great location, and might have been a shorter walk than some Preferred rooms.