We've lived in IL for almost a decade now and generally speaking haven't been too thrilled with the state parks here. Most within 2 hours of Chicago are very crowded on the weekends, and those that aren't are of the 'wide open spaces' variety where you feel more like you are camping in a giant field than the woods. But our first year here, we discovered Morrison Rockwood State Park in Morrison, IL, about 2 hours due West on I-88 from Naperville. This place was literally made for Pop-Up camping. Most sites are heavily wooded, with a good stand of trees between you and your neighbors and the park itself is usually very well maintained. The showers are camp showers, of course, but they do a good job of cleaning them every morning so I usually grab mine right after the cleaning crew leaves. There is a lake at the park (Lake Carlton) and a small marina that sells bait and rents paddle boats, canoe's and small jon-boats with even smaller motors. There are also several piers scattered around the lake where you can walk out and do some great fishing from the shore without needing a boat. I've caught several keeper-sized largemouthed bass and even more crappie and bluegill. There are also Muskies in the lake but I've never caught one personally. And if you don't want to completely rough it, there's also a very nice little restaurant at the marina as well, including a small ice-cream stand. We've personally camped at over 20 Illinois State Parks in the Northern and NorthWestern part of the state, all the way between Bloomington (Weldon Springs), up to Mississippi Palisades and over to Illinois State Beach park near Zion. Morrison/Rockwood is hands-down our favorite every spring, summer and fall. We really think its one of Illinois' best-kept secrets for popup camping.