I don't have a clear cut favorite.
Blizzard Beach: good pretty thrilling slides,big park,good lazy river and nice theming.I'm not a fan of the layout of the slides all being on the mountain so you continuously have to go up the same stairs over and over.The chairlift only gives you access to 3 slides and usually has a wait.
Typhoon Lagoon: mediocre slides,good wavepool and lazy river,only water coaster in Florida and the shark reef where you can snorkel with small sharks.Nice tropical theme.
Aquatica:Good slides,has a fast lazy river called Roa's Rapids which is awesome,nice theming but not as lush or big as the Disney parks but very nice park.Best food and shopping options of all the parks.
Wet n Wild:Little theming,very good thrilling slides and attractions.If you're just into the slides definitely best bang for your buck.