Any suggestions? There will be 3 of us.
You should make sure these places will be serving brunch, but the following places are open on Christmas Day: Blue Duck Tavern, Georgia Browns, Cafe Dupont, and Urbana.
Also the brunch/breakfast at the Hay Adams is delicious and incredibly memorable, so maybe call and see if they will be open (they might because they are a hotel). It's not cheap but it's probably the best special occasion breakfast I've ever had.