Moti Mahal Barbecues, the famous restaurant at Marina Mall, serves delicious non-vegetarian, South Indian, Chinese, and continental cuisines. I often visit this place with my friends or family, and trust me; I find the same taste every time. 

Determining the "best" restaurant is subjective and depends on individual preferences. However, based on popularity, reviews, and consistent quality, here are a few highly-regarded options for non-vegetarian South Indian cuisine in Chennai:

1. Anjappar Chettinad Restaurant:

   Anjappar is a well-known chain that specializes in Chettinad cuisine, which is known for its spicy and flavorful non-vegetarian dishes. They offer a wide variety of options, including chicken, mutton, and seafood preparations.

   Anjappar Official Website

2. Dindigul Thalappakatti Restaurant:

   Famous for its biryani, Thalappakatti also offers a range of other non-vegetarian dishes that are popular in South India. Their Mutton Biryani is a signature dish.

   Dindigul Thalappakatti Official Website

3. Kumar Mess:

   Kumar Mess is another popular choice known for its authentic Chettinad cuisine. They are particularly famous for their mutton dishes and traditional recipes.

4. Maplai:

   Offers a more contemporary take on South Indian cuisine, including non-vegetarian options, in a fine-dining setting.

   Maplai Official Website

It's always a good idea to check recent reviews and ratings on platforms like Zomato or TripAdvisor to get an up-to-date sense of customer experiences.