Even within cities, we have such a huge number of brands, and these brands have superb value.
For instance, try Saravana Bhavan, for the tastiest dishes. No doubt, the food served here is superb, but it is a little costly, as compared to other restaurants. However, what should be noted is that this premium pricing is worth the salt, as all dishes taste the same, throughout the entire city chain, and even abroad, as this chain has followed what is called Total Quality Management, (TQM), standardizing the dishes throughout its entire chain of hotels, within India, and abroad. Am told that for the New Delhi branches, one has to always book in advance.
Ditto for Krishna Sweets of Coimbatore. Please go there to see the long ques of people, waiting to buy the world class Mysore Pak, a South Indian delicacy, made out of the purest form of ghee.
A2B is now a big brand, emerging as a tough competitor to Sararavana Bhavan, both in terms of taste and delivery.
Well, the list is not complete. For the best of organic food, which has a huge amount of protein, prepared only through mud pots, please go to Selvi Mess, in Ponnagar, Tiruchirapalli. One visit is just enough. No other visit would be complete without going again and again. A huge number of other organic food restaurants have also sprung up in various parts of Chennai and Coimbatore.
Madurai is a city that never sleeps. Go there at 11PM, and you will get the tastiest iddlis and hottest dosas, with at least four varieties of chutney. Do not spend more, as these shops, also called as "Aaachi kadais" have a huge variety of both vegetarian and non-vegetarian food. In fact, one is told, food is available, right through the night.
Salem is famous for the thattu vadai, which is a chat item. Coimbatore city is also famous for its cheap bajji, bonda varieties that one can enjoy for just Rs5 apiece. The list goes on, apart from whatever has been mentioned by other members, about Tamil Nadu specialties.