Drake Brothers is great - I recommend the Marrow crusted New York
I'd also highly recommend
Vermillion - Indian Latin Fusion with awesome Cocktails...
Oh and if we're talking cocktails check out
Nacional 27 - for some of the best rum inspired drinks I've ever had.
And should you find yourself by the Navy Pier, talk a walk to the restaurant on the ground floor of the W Lakeshore, for Rose Petal infused garnished martinis and a sampling of contemporary tapas - especially the chorizo-stuffed-bacon-wrapped-dates