MCCC for Sims 4. I mainly started using it when I wanted to have Grim as a playable character & MCCC gave me the option to easily kill off a sim to get him to appear. I wasn't planning on keeping the mod, but then I also realised it made gameplay a lot easier for the oh so slow computer system I'm trying to run the Sims 4 on (if I tried to have my Sims keep up with their needs the non modded way I'd literally be doing nothing else but that in game - at least MCCC allows me to quickly fill needs, without having to constantly type in cheat codes).
Reaper actions unlocker & soul reaper career were my next two mods, because the Sims folks have decided that Grim can't be a fully playable character unless you constantly type in cheat codes or mod your game.