While Corso isn't exclusive to Atlanta—they also have locations in NYC and Montauk—the Italian-style coffee is some of the best I've ever had. And their modern brews paired with a retro interior make for a very inspiring writing spot.
On the corner of one of the most luxurious shopping districts in the city (and directly next door to Christian Louboutin), it seems unlikely a spot for us poor, struggling writers. But it's definitely worth the trek to North Atlanta for an iced vanilla latte and a shady spot on the patio.
More than just coffee, they offer an entire menu of breakfast, lunch, dinner and sweet treats. The seating is a bit limited and can be cramped at prime coffee time, but with bar seats, a large booth area and plenty of al fresco tables, you shouldn't have a problem finding a spot for you and your laptop.
Buon Appetito!