In the suburbs, I love the Morton Arboretum. If you're in the mood for shopping and the weather is nice, Oakbrook mall is fun. There is an old mill nearby, Graue Mill, that sometimes has fun events. Downtown, I adore the Art Institute. A walk through Millenium Park is nice. The Cultural Center is gorgeous, maintains a small but free art gallery, sometimes has free concerts, and will have lots of tourist info/help. Architecture tours are great, walking or river boat. And Michigan Ave is always fun.