I would like to list some of the Chinese restaurants I visited in this trip (and in the past). I will also list some web sites which I think will be helpful to plan Chicago trip.
Lao Sze Chuan (web site here): this is the first Chinese restaurant I visisted in Chicago (2001?). I waited for more than 30 minutes in a hot summer afternoon. The waiting line is much shorter nowadays because there are more authentic Chinese restaurants. It is located at China town. Some of the food (e.g., rabbit meat) are very spicy in my opinion. Get a map here.