Located in the financial district, apx the corner of Deerbourn and Monroe.  On the northwest corner of that intersection is where the old first chicago used to sit on right on the street, with the old bank, owned by god knows who, you will see a glass enclosure that houses an elevator to the lower level, where Nick's is.  The service is beyong anything, their food is so superior, and up to a few years ago the only place where you could still get fresh abolone (shit I know I spelled that wrong, sorry).  It is prepared perfectly, just don't ask the price.  To take someone there for business, or pleasure is really special.  My old boss, many years ago was trying to buy Nick's one barstool, one table, one chair, at a time, he never did complete the takeover.  enjoy

If you feel adventurous, Ras Dashen is a fantastic Ethiopian restaurant. Best meal of my life.

Province was the best restaurant I went to in 2011 and should not be missed. Roy's consistently has great seafood, though I had a wonderful pork chop there this past weekend. If you like Opus One, you will like these restaurants.