Oh my gosh where do I begin???? Go to the Sweet Auburn Curb Market downtown and hit up Sweet Auburn BBQ for some BBQ with a twist! There is also a Grindhouse Killer Burgers inside as well. 

Buford Highway is a great option! Tons of ethnic hole in the wall places that will blow your mind with taste and all reasonably priced!

Ethnic food galore is all around Buford Highway, and the prices are very reasonable. Great Korean sandwiches Lee's Bakeryand they're only about 3-3.50. Also there is a great Columbian restaurant Casa Vieja the address is 3652 Shallowford Rd. I'd go on Friday and get the lunch special. I'd also recommend Panahar Bangladeshi Cuisine. They have all you can eat lunches for $10, and they will give you a coupon for a free lunch if you tell them it's your first time there. You can use it the next time you go.

Busy Bee Cafe, Thumbs Up Diner, the food court at Super H Mart, Pita Palace, Grindhouse Killer Burgers, The Pullman, Jack's Pizza & Wings

Loca Luna! Fantastic authentic Mexican restaurant in  Atlanta! 

Checkout Eats if you wanna get a taste of southern food for cheap. The place features chicken as its main entree. The portions are plenty and you can choose a variety of southern side dishes. 

If you want something ethnic, checkout Lee's Bakery on Buford highway. It's a Vietnamese place with awesome pho and Bahmi sandwiches. They won a bunch of awards.

For late night snack, checkout Octopus Bar. It's a Vietnamese restaurant named So Ba by day and opens around 10:30pm. The menu is consisted of a list of crafted seasonal dishes by the chef. 

Korean (americanized): Takorea 

Korean (authentic): Iron Age (this is in Duluth, 30-40 min away from Midtown)

Italian: Antico Pizza Napoletana, Sapori di Napoli

Cuban: Papi's Cuban & Carribbean Grill

Burgers: Yeah! Burger, Flip Burger Boutique

Venezuelan: Arepa Mia

Mediterranean: Cafe Agora

Indian: Zyka

These are some I can think off the top of my head.

Bonus: Jeni's Splendid Ice Creams has awesome ice cream, definitely check it out.

You should try The Varsity.  It's fast food, but it's an experience and one of Atlanta's "must do" experiences.

Don't overthink it: Sweet Auburn Curb Market. Everyone with you will be happy. There are about 20 different eating options. 

If you like traditional Southern food try Mary Mac's Tea Room.   The food is fantastic and if you are lucky, you might get a back rub too.   

Pappasito's Cantina is probably my favorite restaurant in Atlanta.  The prices definitely vary.  Depending on what you order you can get a good meal for cheap, or an amazing meal if you can drop 20.

Definitely try Mary Mac's Tea Room It's cheap and has great southern food!!! 

Eat the best pizza in Atlanta (and it made the list of best in the US recently) at Antico Pizza Napoletana. http://www.anticoatl.com