The alphamegalog of the cities of Georgia lists the largest city in Georgia for each letter of the alphabet. In this case, ‘largest’ is based on population within the city proper.

Atlanta
Brunswick
Columbus
Dunwoody
East Point
Forest Park
Gainesville
Hinesville
Irondale
Johns Creek
Kennesaw
Lagrange
Macon
North Atlanta
Oakwood
Peachtree City
Quitman
Roswell
Savannah
Tucker
Union City
Valdosta
Warner Robbins
(no X)
Young Harris
Zebulon