If you ever get to Texas, you can't miss the Dallas World Aquarium. Huge tank setups representing different areas and reefs downstairs. The upper part of the aquarium is a tropical rain forest complete with screamer monkeys and giant crocodiles. Just a hint, it really cooks here in the summer, don't visit between May and October, unless ya like to sweat!
the chicago aquarium is awesome! every now and then they have overnights at the aquarium for about 90.00 us dollars per person. also can scuba dive in one of the tanks that they have set up. totally cool!