I live in Athens, but I'm in ATL a lot. If you've got money, places like Club Europe in Buckhead are okay but a little ritzy. Buckhead is your place. I prefer mid-town, places like Smith's Old Bar to see indy rock bands. Virginia Highlands is a nice, but again expensive like Buckhead, section of ATL to go to a classy bar or restaurant.
I'd get a group together and google Atlanta nightlife to find a few spots. Masquerade is a cool place to see bands, and Smith's Old Bar is my favorite place to hang out. Twain's is cool too, and a lot of Adult Swim people hang out there.