There's so much to do in Chicago, I'd just stay downtown - you'll be cabbing it anyway. It's really a short ride to the field museum, planaterium, and aquarium. The museum of science and industry is great - enjoyed it much more than the field museum. I took my 10 year old dd to see Wicked in NYC and it was incredible - make sure to get tickets months in advance (I think my DH got them 3 months out).