Created by Running with Scissors and known for its controversies, the POSTAL games are something to behold, with Postal/Postal Redux and Postal 2 being some of my favourite games ever.
Postal (1997) and Postal Redux (2016), isometric shooters, both have this dry, dark sort of humour, opting to create a more dark and heavy atmosphere, which is pretty fitting considering the content and premise of the game itself.
The rest of the other games are much lighter in tone in comparison to Postal/Postal Redux, being more juvenile, and delightfully politically incorrect, still keeping with the violent nature of their predecessor if one chooses to go postal.