Crush 'n Gusher at Typohoon Lagoon is great fun, and it's 3 separate slides so you get 3 distinct rides. There's also the lure of the wave pool, humunga Kowabunga and the shark reef.
Blizzard Beach has Summit Plummet, but other than that the remainder of the slides are a bit more straightforward. I'd do Typhoon Lagoon for more variety over at C 'n G.