Which CPU will be the with a 1660 Super? Use is partly game dev in unity and mostly gaming in 1440p
About any you wish to use. From a i3 9100F to a 9900K on the Intel side to a 2600 to 3700x on AMD side.
Ryzen 5 2600 or Ryzen 5 1600 AF would be a good option.
Would help if you had a budget. Generically, I’d say either an R5 3600 or R7 2700 given the video card and that you’re doing some dev work.
And 2700X is back down to $165, an even better pick!