Truly one of the best dining experiences I've had in Chicago. India House is the no-brainer for Indian lunch buffets. Located downtown, about a block west of the Grand Red Line, it's convenient and worth the trip downtown.
The buffet is usually 10.95, but is 11.95 on Sundays. It's got everything you could want and then more. Unlike most buffets, you don't get the feeling that the food has been sitting under heat lamps for hours before you showed up. Fresh food is put out frequently. The waitstaff is attentive and courteous. If you're a drinker of Indian beer, you'll be pleased with the selection here.
The restaurant itself if very nice with a elegant, quiet, and relaxing atmosphere, perfect for a good lunch with an old friend or relative. Make sure to call ahead on Sundays, because it is a popular lunch stop, but don't miss this place.