I've been lightly reading over this thread, just a few observations:
Rush Street: Did anybody mention Rush Street?
Ditka's Restaurant or Harry Caray's?
Giordano's Pizza gave me wicked food poisoning, and had to fly at 6am the next morning. A pox on them!
Ed's is very fun. Food is decent. Wait staff is a hoot.
Billy Goat Tavern is underneath the Chicago Tribune building. Cheeseburger is nothing special, but atmosphere is pretty cool. And they have beer.
Museum of Science & Industry is great, but its in SOUTH CHICAGO. And the L does not go directly there. It's about a mile away. NOT A GOOD NEIGHBORHOOD to be in, so take a cab if you go there.
Second City Comedy Club rocks. Lots of guys & gals from there end up on SNL.
Have a Vienna Hot Dog and an Old Style Beer.
Frank Lloyd Wright stuff in Oak Park.
Art Institute is awesome (if you like art).
Have fun, be prepared to spend money.