Either way you could take MARTA to the area around the GA Aquarium. Get off at the Peachtree Center Transit station. It really depends on hotel preference. There is a Hilton Garden Inn right across from the aquarium. Several Marriott properties close to the MARTA station.
I guess it depends on what else you want to do.
A suggestion. To avoid hotel shuttles which can take some time, you can book a hotel next to the GICC conference center Home - Georgia International Convention Center. The rental car train stops right at the GICC center, so less hassling with waiting for shuttles and worrying about space. Runs every few minutes, so painless in the morning to get back to the airport. There are several Marriott properties right there.
There really isn't much around any of the airport hotels, so for food, etc. you have to rely on the hotel or Uber or car rental. That may factor into your choice.