On our move to Ft. Benning (1hr from ATL) we stayed in the Hampton inn... really nice but pricey...$160 a night and then parking.. but your not going to find anything super cheat if your in-in the city
Downtown Atlanta is wonderful....Make sure you go to Atlanta Underground and wear very comfortable shoes. Also remember to stay in a crowd as with any large town. Atlanta is so much safer than it was in the 70s. Great job Atlanta. Some neat clubs also. Dont call it "Hotlanta" for nothing.