What part of Illinois? If you're in the northern suburbs, there's Old Orchard Aquarium (Skokie), Living Sea Aquarium (Park Ridge), Old Town Aquarium (Chicago), and then some other ones I can't remember right now.
yeah i got one down the street from me all of there fish they have are so small now i got my albino oscar and the jd from there and my other oscar but jumped out and died :-( bump
Its a drive, but Aquatics Unlimited SW side of Milwaukee, close to interstate is excellent. 2nd largest selectionj I have seen (Aquarium adventure Schaumburg No. 1) although for FW fish only, Aquatics Unlimited may have a better selection.