I've known it to be the Hilton Garden Inn at State and Grand. (On Grand, at the corner of State Street)
It's a great hotel, centrally located between Michigan Ave (3 blocks to the east) and not too far of a walk to The Baton (a couple blocks to the west, and then a couple blocks south). There's also a grocery store across the street, Nordstrom just east of the hotel, and a steakhouse and P.F. Chang's on the same property as the hotel.
Chicago, as Im sure you know Fran, is not known for their cheap hotel rooms, so I would TOTALLY see if there's a "Continental Rate" for the Hilton Garden Inn.