Many of the worlds tallest buildings and two of them have sky decks, Navy Pier, Millenium park, Worlds best shopping, dining, theaters, Museums, etc. Many great Bus and Boat tours.
Vince Vaughn!!! Haha, J/k. The downtown area is awesome. Lots of places to shop, I love going to Chicago. Dress warm! The windy city gets pretty chilly! :) Have fun!