1Renaissance Hotel
Probably the best spot of all for logging is the Renaissance Concourse Hotel in the northern part of the airport. The rooms form the sixth floor and up with balconies look out over runways 8L/26R and 8R/26L and the concourses. Rooms 1022 and 1025 are confirmed as having great views.
Photography is possible with 200-400 mm on the north western most runway, but as you are facing south most of the day, you would better pick an overcast day.
2FBO & Cargo
The parking lots of Mercury Air Center and some small cargo buildings off Toffie Terrace allow part of the cargo aircraft and bizjets/props to be read. Photos are difficult to take, with the sun facing you most of the day, and a fence and handling equipment hampering you.
3Sewage Treatment Plant
This spot is at the entrance to a sewage treatment plant on Lake Mirror Road, just off the I-285 service road. This spot gives you a good view of traffic landing to the west (runway 27L) or taking off to the east (runway 9R). Photography of traffic can be done nearly all day.
4Taxiway to 10/28
With the opening of runway 10/28 some roads south of the airport have been cut off. The Airport Loop Road dead ends at the taxiways to and from this runway. The taxiways are right in front of you, with the fence descending to the tunnel. Any aircraft landing on runway 10/28 will have to pass this spot, so you will not miss any of them. Although partly obstructed by bushes, most aircraft landing or taking off on runway 9R/27L can also be read, as are some aircraft at the terminal.
You can take photos of taxiing aircraft here from about noon until sunset. This is only possible in south eastern direction; otherwise the fence will be in the way. A CRJ requires about 400 mm on the far taxiway.
5Ruby Tuesday
Another spot is the parking lot of the Ruby Tuesday restaurant, with the entrance at Sullivan Road. It offers a good view of traffic departing from runway 27L. The sun is good for photography pretty much the whole day, but in summer until about 5 or 6 p.m. For 737s almost a full 300 mm is needed and for a 777 it's about 220 mm. Not the greatest spot but ok.
6South parking garage
Many people watch the traffic from the roof of the South Parking Garage (4th level). Good overview of runways 9L/27R and 9R/27L and part of the concourses. If traffic is operating to the east, planes will be taxiing to runway 9L and will pass directly in front of the garage. The down side is that - aside from the parking fee - you can expect to be approached by a security guard if you are taking pictures. They say it is not allowed, but from other's experience the Airport Operations Department does not have a problem with people photographing at this location. As it is facing south, the best time for taking pictures is in the late afternoons.