We stayed at the Sheraton on the Falls hotel when we visited the waterpark. The hike to the waterpark is a lengthy one from this hotel. You can walk through an arcade, some walkways, past the Hard Rock Cafe, through to the Crowne Plaza (the Crowne Plaza is the hotel that is directly attached to the elevator to the park) and then finally to the garage elevator (and there is only ONE elevator to take you up to the waterpark, so it can become congested when you go prime time. The only way to enter the waterpark is via an elevator. THe waterpark is built on the top floor of a parking garage!
I liked the Sheraton, and personally think it is the nicest one of the four. We had a beautiful room on a high floor with a view of the falls, and a fireplace! We were there on an evening when there were fireworks over the falls so it was fabulous and made the hike to the park worth it! We had dinner at the hotel and because we were there early enough kids eat free at the buffet with a paid adult. The girls were welcomed with a kids' welcome loot bag thing which they liked. If it is within your budget, I do not recommend the "traditional rooms"..these are located on the lower floors, and the hallways have not been refurbished, with poor views.
Notes about the park:
We first arrived at around 2ish on a Sunday and the park was at near capacity because there was a group event at the time. There were only small lockers for our wallets and valuables for rent, and I had to bring our bags and clothes INTO the water park!!! We left the park for dinner but returned in the evening (and the next morning) , and finding lockers were not an issue at this time. The change rooms are big with only a couple of private rooms. The family change stalls are nice and big too. I really liked this as even Great Wolf Lodge does not offer family change rooms. The towels are your typical waterpark towels: small and thin. I highly recommend bringing your own.
Hope this helps!