Stormalong Bay shared by Disney's Yacht and Beach Club Resorts is by far the best. It is long and winding with a sand bottom, waterfalls, whirlpool and a great slide. It is nice and large and great to lay by.
SAB get the most votes for the best pool on Disney property. Aside from that, I love the pool at AKL. The slide is far from the best...but I love everything else about it. It is a huge oasis with amazing landscaping. Where else can you have a morning swim and hear flamingos squawking for breakfast?
SAB is the greatest Disney pool by FAR. No pool compares. Sand-bottom pool, complete with sand play area, lazy river, whirlpool, everything possibly imagined. Next best pool slide wise is BW because it has a roller coaster themed water slide. AoA has a big pool, but a big pool isn't complete without a cool slide and that is the problem with the Value pools. CSR is also very cool, with the large mayan pyramid slide and structure, and water-spitting mayan sculptures.
Another vote for SAB. It is, IMO, hands down the best pool on property. That said, how old are your kids? When my kids were younger we stayed at the value/moderate resorts and they enjoyed those pools, especially CBR and POFQ. We didn't start staying at the BC until they were a little older (my youngest was 7) and all strong swimmers. I have seen people with young kids complain that SAB was too big and overwhelming for younger swimmers. So if that is a consideration, let us know and we can help you out further!
I'm in the minority as I think the volcano pool at the Poly is the best pool on property. The pool is great, IMO, as it backs up to the beach with a distant view of the castle while swimming. While SAB is a nice pool, it's not our favorite as there are others we like better (with the Poly pool being our favorite).
We have stayed at Poly, CR, BWI, BC, and AKL. Our favorite pools are at BC, AKL, and Poly. It's a toss up, and really depends on what you are looking for. BC is amazing. It is huge, with a lot to offer. Poly is lovely, with the beach right there, and the view of the castle. AKL is a lot of fun! Especially if you take the shuttle van over to Kidani. Our kids loved the water park/play area next to the pool! They had great activities during the "pool party" hours and gave out interesting beads. I think their bar was a little better, overall, too.
Stormalong Bay is amazing. It's the best hotel pool I've ever seen. It's got a lazy river and a sand-bottomed area. It really is a mini waterpark. I am hoping that I will get to stay at YC/BC at some point again in my life, just for that pool!
As a whole, I find Disney's pools rather unimpressive, especially compared to some offsite hotels that really have out of this world pool complexes. However, as other have mentioned, SAB is just fantastic!!! It really offers everything, as is it's own "mini" water park. IMO, no other onsite pool compares! It's worth it to stay at the BC/YC for this alone.
