If you live in Chicago, a membership is more than worth it. If you're visiting, this is a must see for your kids. My son and I are there at least once a week. He just turned 2 and he absolutely loves it. There are lots of exhibits where the glass goes all the way to the floor, so little kids can really get close to the action. There's also a play area for kids by the penguins along with booths where you can have lunch. You can either bring your own food or buy at the cafeteria - I recommend bringing your own as the cafeteria food is pricey and not so good. There's a new place with better food but its also pricey and only open on weekends. Spring for the Fanatasea tickets, its totally worth it.

The staff at the Shedd are really helpful and super friendly. I could not recommend this more for families with young kids.