I think Portillo's is overrated. I heard all of these good things about them, then was severely disappointed. Plus, didn't they get in some trouble with the health board a year or two back?
I wasn't much of a fan of they boat/architecture ride, either. It was cool at first, but went on WAY too long.
One of my favorite things in Chicago was to go to Shedd Aquarium. I'm an animal nut, so I loved that, and the dolphin show was great, and included with admission.
My number one place to eat in Chicago is Smoques. Every other brisket that I eat for the rest of my life will be poorly compared to Smoques. Excellent ribs, too. It's on Pulaski, which is a ways from Michigan though. It's been awhile, but I think you can take Michigan all the way to Pulaski, then take a right on Pulaski. Just make sure you go in the afternoon, and leave before it gets dark. After lunch at Smoques, Wrigley Field is just a few miles down the road as well. I believe Addison is only about a block from there. Any sports fan has GOT to see Wrigley Field at some point in their life!