Went to a great place on my last visit to Chi-Town last March called 1492 Tapas. Here is the URL: http://www.1492tapasbar.com/
First, get a table in the basement. I believe they have 3 floors. It is was cozy, intimate and just - well - great!! The service was unbelievable, the food was wonderful. Order lots of different tapas, share, plus share some wine, candle lit! Probably one of the best meals I have had in a long time.
We spent $100 including wine, tip, food. But again, you will really appreciate the place more in the basement. Check it out!
Good Luck!
^yes 1492 is also a great idea. Great tapas and actually authentic, I might add!