I'm going to try and do some side by side comparisons of the type of rides each water park has. AI=Adventure Island, AQ=Aquatica, and WW=Wet n' Wild.
Inner-tube Slide: AI-Aruba Tuba, Calypso Coaster, Key West Rapids, Everglides (toboggan) AQ-Whanau Way (4 slides), Tassie's Twisters WW-The Black Hole, The Blast
Body Slide: AI-Caribbean Corkscrew, Gulf Scream (2 slides), Water Moccasin (3 slides), Runaway Rapids (Kids slides) AQ-Dolphin Plunge (2 slides (WITH DOLPHINS)) WW-Der Stuka, Bomb Bay, The Storm
Mat Slide: AI-Riptide AQ-Taumata Racer WW-Mach 5
Family Raft Slide: AI-Wahoo Run AQ-Walhalla Wave & HooRoo Run WW-The Surge, Bubba Tub, The Flyer (4 person toboggan), Brain Wash, Disco H2O
Each park also has a lazy river and wave pool. Obviously each ride has it's own features that make it unique, but that would be one long post. I would consider Wet n' Wild to be a more thrilling park, Aquatica exotic, with Adventure Island more all around stuff (good for families with young ones).