If I must choose, I'm more sandbox than simulation. I have a loose story in my head and I use the Sims to play it out.
That said, I also want the game to throw curve balls at me (that I can cheat away if they really disrupt things), present challenges and opportunities for my sims to grow in ways I didn't expect, and take care off all the "background" setting elements of the story I'm telling.
Basically, I treat the Sims as a single person TTRPG, with the systems as the rules and the AI as the dice. (And mods as house rules.)
