We went to the Georgia Aquarium after going thru the Coca Cola Museum as they are in the same area. It was expensive at $36.95 plus tax but very nice. We were able to see a dolphin show and a sea lion show. The behind the scene tours were sold out but we had heard they are very interesting.
Would highly recommend, but eat before you go or plan yo eat after as the cafe prices for drink. fries and burger is $17.95 plus tax.
Take your time as they do not limit attendance and there were lots and lots of people.