It depends what do you want to do in Turkey as work wise, also
it varies on what kind of weather do you enjoy.
If you would like to see no snow then west and southwest side is
great! If you want to see more snow then east side is pretty cold
and snowy and goes on.
The biggest cities are İstanbul, Ankara then İzmir. There are
millions of people in these cities and better to live for a
foreigner.