Whichever airport you fly into - and see if you could fly into one and fly out of the other - use public transportation. It's cheap, it's easy, it's reliable, and it goes everywhere you might want. Cabs are ridiculously expensive and the L is GREAT!!
You'll need a few days to see everything - if you can hold off and wait until April when baseball season starts, go see a Cubs or White Sox game! Again, public transit is the key. Don't forget also to do the top of the Sears Tower AND
the Hancock Building - you'll know why when you do!!
Is Gino's East Pizza still in downtown Chicago? Best pizza I have ever had in my life - the line was a mile long, but it was well worth the wait!!
You'll understand why Chicagoans say, "this city would have 50 million residents - if it wasn't for the winter!!"
Pan Am:The World's Most Experienced Airline - P(oor) S(ailor's) A(irline): San Diego's Hometown Airline-Catch Our Smile!