This is one of the best bakeries in Atlanta my family orders from here for all our special events. The red velvet cake is our favorite. All of their cakes are really good.
If you're looking for a DELICIOUS cake that you can get with very little advance order (usually 24 hours is enough, but often they have some prepared that you can just grab & go), Piece of Cake is a great bakery. Their cakes are moist, their icing is decadent, and they're easy-peezy to get in and out of with locations all over Atlanta. They usually have some vegan cupcakes too, which helps accommodate when you have a few folks who can't enjoy the cake.