We have a membership here that allows us to visit other childrens museums all over the country. This is by far the best one we have been in.
There is a ton of stuff to do here at the museum. There is a play city with a diner, where kids can cook and serve meals to patrons (plastic food of course), a super market where they can grocery shop and ring up their purchases, a vet where they can play with stuffed animals and take xrays and diagnose issues. There is a fire station, a tv station. Outside of the city, there is a huge climbing structure which is even fun as an adult chasing your kids around as they can end up on a different level of the museum than you. There is a rock climbing station (its not too huge, but very fun), and a science level at the bottom level. Outside there is a large water play area.
They have a lot of travelling exhibits that come through all year long that make it fun and different every time we visit.
If you have young kids (up to age 10) this is THE best place to visit!