Heading to Chicago for a couple days

[thac]

My girlfriend are taking a trip to Chicago for the weekend,wWhat are the main attractions that we shouldn't miss? So far we're going to Grant Park, Millennium Park and the Magnificent Mile.

We don't wanna go to the Architecture museum or anything really historical, and she's been to the Sears Tower already so I don't really wanna go there. Anything cheap that we can spend time at basically is what we're looking for.

Also, we may go to that big aquarium thing.