I could go to Rincon De Buenos Aires solely for their chimichurri. I am a huge fan, and I just love, love, love it. It goes great with their steaks and bread. For only $2, you can get unlimited bread and chimichurri.
I also enjoy their very large salads. You can definitely share one with 2-4 people. Don't forget to try their empanadas. I have yet to try the ham & cheese, but the beef, chicken, and spinach are all delicious. I definitely recommend Rincon De Buenos Aires for lunch!