In order of proximity:
Petland: average to limited selection of fish, high coral prices, not really a "reef" store per se, lacking service.
Petco: limited fish selection, no corals, no real equipment
Pet Fun: atrocious fish selection, horrible corals
Upscale Aquatics/Plainfield: unreal and unreasonable prices, just-ok selection
Reef Plus, North Aurora: good fish selection, he'll order everything you need, average to OK coral selection, reasonable prices
Deep Reef, Downer's Grove: Great and frequently updated fish selection, reasonable to high prices on fish, High prices on corals
Reef's Edge: Never been
Tropicquatics, Lombard: good to great selection on fish (depending on the day), reasonable prices, average coral selection, high prices on corals
Rod's Reef: great selection on corals, great prices on corals, few to no fish, good prices on fish, will order for you, worth the drive all day long.
After this, you're getting closer to distances like Sharky's, Ocean's Floor, etc...