Don't be the rube that goes there and eats at Gino's East.  LOL
Just a short list.

The Girl and The Goat is a great place.  

Dive bar style with awesome burgers--The Billy Goat Tavern

I'm VERY partial to Carmines on Rush Street (1043 Rush I think)

I've also heard good things about The Purple Pig

Ditka's oysters are the best

I'm also addicted to pf changs' lettuce chicken wraps

So many choices....

For sushi/ASIAN downtown: Sunda, oystar, slurring turtle, ramen-San, roki, hub 51, sienna tavern,  

Steaks-rpm, Kinzie chophouse, masteros,

Fast food- the shake shack

Various- Paris club, Hubbard inn,  (whole role of Restraunt's on Hubbard street) untitled, fig & olive  

Chicago is one of the best cities for cuisines.. There a Restraunt for any taste buds ....  

 (Google or yelp it will help a lot.. Also venture into other parts of Chicago, easy access cuz we have one of the best public trans system in the country!!!! Neighborhood like Lakeview, Lincoln park, wicker park/Bucktown, old town, gold coast all with really superb Restraunt's  

BON APPETITE!!!!

Like cheese and wine?  Visit Bin 36.

Le Colonial on Rush St is a wonderful Vietnamese place, great food and ambiance.
I second Carmine's - be sure to sit downstairs so you can enjoy the live music.
Mercadito is fantastic Mexican place, louder and busier scene.

Thank you!

For all the great suggestions.  I really appreciate them