A couple great places, I think, are Brasserie Jo and the Everest Room. Everest, in particular, does fantastic work pairing wine with food.
Both of Rick Bayliss's places are great -- Frontera Grill and Topolombompo.
I've got a serious soft spot for the Ritz Carlton Dining Room's Sunday brunch!
The original Morton's on State Street is my favorite steak place. Ever.
Gino's East, I'm sad to hear, has dropped off a bit on the pizza front. I've been doing Giordano's mostly of late.
I think Chicago is really underappreciated on the restaurant front ... there are so many fine places.