I don't know which area of ATL you're looking for, but MegaGranite in Coweta Co. is popular. Around here, they are the best in terms of pricing.

Here is a link that might be useful: MegaGranite

Stone Connection off of Peachtree Industrial in Norcross is a nice showroom as well as Granite Depot off of Jimmy Carter and McDonough. I also loved (where I got my granite)was UGM, Universal Granite and Marble close to Buford Highway and Beaver Ruin Rd intersection. There are also quite of few on Jimmy Carter between Buford Highway and Peachtree Industrial. Also one off of Oakbrook Parkway in Lilburn. I have been to quite a few (lol).

I used 'A Polished Finish' out of Loganville. They came all the way up to the mountains(Jasper) to do our work.
Great selection, incredible pricing and they did exactly what they promised and when. Owed by a very nice young couple. link below

Here is a link that might be useful: a polished finish

We found ours at A&S Marble and Granite Imports in south Buckhead (75 and Howell Mill) 404-603-8182.

We also checked out Georgian Stone, Compass Stone, UGM, AGM Imports, Marmi Natural Stone, MSI, and G&L.

Since you have been looking & if you have now been to UGM (great guy, delayed going to lunch to show me around & he knew there was a small chance I could be his customer) you probably have heard the question, "Whose your fabricator?" UGM guy told me he could not recommend a fabricator, but he worked with hundreds around the SE. Ultimately, I got a list from neighbors, started calling with some thoughts of what I wanted & they got me into more distributors (like UGM & Stone Connections).

I'll be glad to share my list if you want, but I also found that if you have a smallish job (possibly not your kitchen) & want to look at a cool bone yard, Inman Park Marble & Granite has great stuff. They were my fabricator for a Master Bath remodel (Emperador Dark Marble). Their bone yard has some beautiful exotics in small & medium amounts & will give you reduced prices on these pieces. I'll definitely pursue once I redo the other baths, but right now am working on the kitchen . . . Good luck.

UGM may be closing so its possible to get a good deal there. Many of their staff has been let go. Hopefully things will get better and they'll be able to hang on. They were great to work with. Probably the same manager, Tom, maks spoke about was there for me too. He let us come over when they were closed, he put all the lights back on in the warehouse and stayed an extra hour with us. They have great customer service. Its a shame they can't hold on in this economy.
I also have a fantastic fabricator/installer if you need one in the Atlanta area that will also help you find your granite.

Thank you to all.

Nursetammi, please pass along the name of your fabricator/installer if you could. Thanks.

maks2000 - Thanks for the recommendation for the yard with small pieces. We do have a very small island (45" total) and have been looking for a specialty piece.