Four neighbourhoods, four different trips. The Old Quarter is the obvious answer and not always the right one.
District 1 for a first visit, District 3 for value, Thao Dien for a longer stay. And one area to choose deliberately rather than by accident.
Six distinct areas across two places forty-five minutes apart, and what each one is actually like to wake up in.
Six parts of the island with six different holidays. Choose the coast before you choose the hotel.