Listen: when you have a chance to ride in a pretend fire engine in air conditioned comfort, you take it. The Children's Museum is an affordable bit of fun during our blazing season (free on certain days of the month, although predictably a little nuts) and even cheaper with a membership. The place was designed to have entertainment around every corner and the kids might even learn something in the process.
Runners up:
2. Brandi Fenton Splash Pad
3. Breakers Water Park