Georgia
noun: Georgian(s)
adjective: Georgian
Germany
noun: German(s)
adjective: German
Ghana
noun: Ghanaian(s)
adjective: Ghanaian
Gibraltar
noun: Gibraltarian(s)
adjective: Gibraltar
Greece
noun: Greek(s)
adjective: Greek
Greenland
noun: Greenlander(s)
adjective: Greenlandic
Grenada
noun: Grenadian(s)
adjective: Grenadian
Guam
noun: Guamanian(s) (US citizens)
adjective: Guamanian
Guatemala
noun: Guatemalan(s)
adjective: Guatemalan
Guernsey
noun: Channel Islander(s)
adjective: Channel Islander