YES! THE WATER PARK IS AMAZING!!! Probably the best around these parts. I suggest being there for the opening of the water park and getting on Mammoth first thing (the line can get over an hour sometimes during the summer). Cheetah Chase and Wildebeest are both amazing too.
As for the dry side, Voyage and Thunderbird are the highlights, but recommend everything else as well. If you're near Thunderbird and it's running, ride it because it can break down a lot depending on the day.
Not sure if you know, but Holiday World gives you FREE PARKING and FREE DRINKS!!!