Bermuda -
Are you interested in primarily the food, and don't care about the restaurant's ambiance? Or do you want a mixture of both?
If you're interested in primarily the food, the ethnic places on the Great Neighborhood Restaurants list will probably appeal to you, but you should know that certain of the restaurants are located in less-gentrified neighborhoods and have the ambiance of an Arby's (Xni-Pec comes to mind for that).
I have to respectfully disagree that our "downtown" is filled with expense-account places. (And by "downtown," I mean the Loop, River North & the Gold Coast; Chicago doesn't have a specific area called "downtown"). There are plenty of places in our "downtown" area that are affordable. Also, while I'm all for the neighborhoods, a first-time visitor will probably appreciate the energy attendant to the downtown area. Bermuda, I hope you are not discouraged - Chicago's downtown is nothing to sneeze at architecturally and, IMHO, doesn't look like every other city.
Having said that, I think David Burke's Primehouse is a younger, hipper and better, IMHO, steakhouse than many of the old standards, and is located in the bottom floor of the James Hotel in Gold Coast area, a snazzy boutique hotel. Capital Grille is an Atlanta-based chain and not particularly Chicago (although Burke comes here via NY but we like the way they dry-age their steaks).
I would also suggest
Avec, which is a nationally-known Mediterranean-focused small plates restaurant with an excellent wine list, trendy, communal dining and a energetic vibe.
Around the corner from Avec is
Sepia, a contemporary American restaurant which has been getting good reviews and is also lively. Both restaurants are located in the West Loop neighborhood.