Love Valleyfair. Bring your own food and picnic i...

Love Valleyfair. Bring your own food and picnic in the lot. Their food is super expensive, as most amusement parks are. They have a plethora of rollercoasters, a waterpark, and a great "kids park." There are lots of places to get snacks and drinks. A few restaurants. A few shops. They have caricature artists and face painting stands.
You have to ride Renegade before you leave! Wild Thing gets all the hype, but Renegade is where it's at. The zipline is also crazy fun, but isn't included with your ticket. You do have to pay more for that. Make sure you wear a swimsuit or clothes that dry quickly so you can enjoy some of the water rides even if you don't plan on doing the water park.