There's a Marriott on North Sedgwick? That's new to me. Sedwick is mostly a residential street but for the sem-famous (or notorious) rib joint, Twin Anchors.
How about the Mariott on North Sedgwick between Willow and Eugenie? Or the Hyatt at McCormick Place?
McCormick Place is pretty far away and pretty inconvinient unless you have a rental car.
Like I say, I would think any of the Michigan Avenue type hotels (including Marriott, Four Seasons, Ritz, Penisula, Omni (two), Drake, etc.) would fit the bill. Just take the El.