I only spent time in ATL on business, but it was significant time. I really loved virginia highlands—had a really cool atmosphere with lots of good food and bars (trivia nights, etc.). Based on your username, it sounds like you should check out Buckhead—that place has a hopping nightlife with clubs and it sounds like there are some affordable apt complexes in the area. If you want to spend a little more, the Atlantic Station area is up and coming and pretty nice.