We stayed at the Hard Rock on January 27th, 2009 for $125/night. It is located on Michigan Ave, just two blocks from the Mag Mile, two blocks from Millenium Park, and five blocks from the Chicago Art Institute. Our hotel room was very nice with views of Michigan Ave and a unusually comfy bed. The hotel even offered free coffee in the lobby every morning and free wifi in the rooms. Parking was $45 for valet and $30 for self parking. The staff was very helpful with all of our request. 
