Actually the Shedd has changed quite abit since you and i were kids. i was just recently there about 5 months ago, and they had about 20 60gl reef displays,plus the new exhibit on the lower level, which has a 10Kgl tidepool with a 500gl per cycle wavemaker in the center. there is soo much to see there, and the Field Museum and the Planetarium are right there as well.
But i think if someone really wanted to see some spectaular reefs, travel to tonga, guam, hawaii or figi and scuba!