Of the courses I've played:
Arrowhead Golf Club - nothing special.
Balmoral Woods Country Club is pretty solid.
Bolingbrook - Lot's of people like it, but I can't stand the course. A bad Art Hills course. The clubhouse there is very nice and a monument to a former mayor.
Poplar Creek - pretty bad. Lots of water.
"Crane's Landing" Golf Club - The old Linconshire resort course is essentially an executive course that is always packed.
Eagle Ridge - The General is really good.
George W. Dunne National - A very good forest preserve course, but tee times are very hard to come by and any time after 9:00am on the weekends mean a 5+ hour round.
Golf Club of Illinois - Not too bad.
Mistwood Golf Club - I think this is closed this year for renovations.
Odyssey Country Club - so-so.
Orchard Valley Golf Course - so-so (same designer as Odyssey).
Prairie Landing Golf Club - I like Prairie Landing, a fun RTJ, Jr. course worth checking out.
Ruffled Feathers - The only "Dye" course in IL, this is a hot mess. Too many homes/condos WAY too close to the holes...it's not a very nice experience.
Stonewall Orchard - A nice Art Hills course which has no housing on the course and has some nice holes. People complain about the 18th hole because of a blind second shot on a par-5...but it's not that bad.
Water's Edge - pretty underrated with some nice holes.
Whisper Creek - Boring.