I did my FAA PPL at Cushing Field, about 40 miles to the south west of Chicago in 1993.
Not sure whether the same people are still there, but the field was owned at the time by Charles Cushing, who I found to be a very nice and personable guy. The aeroplanes (a mixture of C152's and C172's, with a single Citabria) were all okay and well maintained, and the hourly rates weren't bad either. I seem to recall the company was known as Flying C Leasing.
I'd recommend them, but as I say it was over ten years ago and they may have moved on. Let me know if you do manage to drop in there, as I'd love to know if they're still there and maybe go back and fly with them again one day.
Got a lovely memory of flying into Meigs (

) and chugging up and down the lakefront one day, a mile out over the water, and marvelling at the Chicago skyline from 2000'..... <sigh>... happy days, they were...