Navy Pier is to be commended by this reviewer for having a little something for everyone. Granted, parking on Navy Pier is expensive, and it's not the easiest thing to take public transit out to the Pier, but it's all worth it. The view of the city at night from the top of the Ferris wheel is unparalleled, and strolling along the Pier on an uncrowded evening is simply magical. Although summer afternoons and evenings pack the pier with tourists, this local enjoys the off-season just as much.
Logistically speaking, you've got plenty of food options, ranging from McDonald's to formal seafood restaurants. Bathrooms are hidden along the pier corridors, and plenty of fun houses, simulators, and games will keep the kids entertained.