We prefer Massanutten to Williamsburg in the summer. Williamsburg doesn't have any resorts with any really nice pools and everything is off site and outdoors and I just don't do well. In the summer when it can get really hot the pools that are at many are filled to capacity.
At Massanutten we don't hit the water park more than once a week or maybe a full day and an after 5 but that's it. There is still a fairly large outdoor pool at the woodstone rec center, the mountainside one has a diving board. There are free wiffle ball and kick ball games almost daily for the under 12. We like to rent an adult and a kid size driver and get a large bucket of balls and just wack balls down the range-we take turns and for less than $10 we have a great afternoon 1-1.5 hour activity. We hit the geo dome bungy jump one evening or morning when it is cooler.
So these pools are free:
Bungy dome is about $7 for 15 minutes but it wears them out.
For around $30-$35 we get a combined Ropes course, climb and mega zip line pass
https://www.massresort.com/play/family-adventure-park/
So one day of water park- if you go on the tour they are free- I don't necesarily recommend that route to the water park. I search early and can usually find discounted tickets in the $25-$30 range. I think full price tickets are nearly $40 and that is too much.
Water Park, Adventure pass combo and bungy jump the kids are up to about $75 in activities. Everything else we do are the free activities. We do spend about $5 total as a family on a couple air hockey rounds and billiards but the ping pong is free.