Beach Club and Yacht Club share the phenomenal Stormalong Bay pool complex. It has a huge, pirate-themed water slide that is unsurpassed at any other WDW resort. It also has a lazy river, mini whirlpool, sandy bottom pool, and 3 hot tubs. Best of all, access to Stormalong Bay is restricted to resort guests by Magic Band (scanned by a CM, not just a gate), so there are no crashers to overcrowd the pool complex.
Another is Animal Kingdom Lodge, which gives all guests (regardless of whether they stay at Jambo House or Kidani Village) access to both sets of its feature pools. The feature pool at Jambo is huge, has a water slide, backs up to a savanna, and has a big, shady hot tub. The feature pool & hot tub at Kidani are a bit smaller but there is a better spiral water slide, and a young kids' water play area. It gives some variety to be able to use both pools during your stay. They are within walking distance (7-10 minute walk), or you can take the resort's free shuttle.
Polynesian Resort has a nice pool & Volcano-themed slide, but I found the pool crowded the time we were there. The Boardwalk also has a nice spiral slide, but its pool isn't huge, and you have to be okay with clowns to enjoy that pool, as the base of the slide is a giant, open clown's mouth.