I am about 4 hours from Six Flags Great America.
Then, we also have Bay Beach Amusement Park (about 10 minutes from my house, if that). It is an amusement park that was built on city land in the 1930's. There an now about 20 or so rides there, including a merry go round, Tilt a Whirl, swings, bumpercars, and one of those giant slides that you ride down on burlap sacks. You purchase tickets for the rides. For years and years and years, the rides were one ticket. Each ticket cost 10 cents!!. Then some of the rides went up to two and three tickets. Finally about 3 years ago or so, they had to raise the price of the tickets to a quarter a piece. We are out at Bay Beach about a dozen times, if not more, a year. My kids love it, and I still love it!! I actually worked there in the summer for 4 years and had a blast! If anyone is up near Green Bay, I would recommend it for something totally different!!