Essential as in pretty much everyone agrees are good and worth having, I know no mod is essential in the literal sense, and opinions will change whats essential to each individual.
Looking for a bit of a list/collection cause otherwise I’ll go down the rabbit hole and end up modding my game to much to be playable… Which I wish was a joke, but that happened last time I got my itch on for city building, lol.
Move It, Precision Engineering, TMPE.
I’ve not played in a long time, but those are the three that EVERYONE used to run as a core setup.