We just went to Legoland this week- my boys (6 and 3) loved it. We stayed at the Comfort Suites in Schaumburg and it was very family friendly. Fyi- Subway and Burger King have Legoland coupons. Also, at the hotel I found a $5.00 off admission coupon. Comfort Suites also has a Legoland package which includes hotel room, 4 tickets and a large pizza for $169.00.
When I go downtown I park my car at the Cumberland ramp and take the El from there. Cumberland is 2 stops from O'hare and easy to get to, that seems to be where the car traffic gets heavier too.
I have taken my boys to the Shedd, the Science and Industry Musuem, and the Field Museum. They did well at all of them. The Science and Industry Museum is further down Lake Shore than the other ones, and we drove to that one.
I sell Scentsy!!!!