Key to the City

Per the in-game notes on the achievement - this does need to be in a single city.

The requirements for each unique building are clearly listed in the game, as is whether each has been unlocked/built - so this is easy to track.

However it will take a while as some buildings require hundreds of regular buildings to have upgraded to level 5 - so your biggest enemy will be simulation speed slowing down causing this to take forever as your city inevitably grows.

Its probably best to leave the (easier) regular residential ones to last and focus on commercial/industrial - either way it'll take a loooonnnng time. Almost as long as You Little Stalker!