AKL - the Savannah is fun. Zebra domes at Mara
Poly - The Dole Whip is always good.
While not on your list, at Wilderness, the geyser is fun to watch.
GF - not sure if your kids would appreciate it, but in the evening, the Jazz band is very good.
In the evening, watching the Electric Water Pageant from Poly/GF/Contemporary.