I love evil Sims. They are so much fun to play, especially with mods. Nice Sims are too... real? Like, in order to have a nice or otherwise relatively normal sim, you kinda have to play them like a real person which can get too real. But evil sims can be played like a cartoon supervillain. My current crackhead is a hideously deformed twig named Shpingle Bab

Edit: also, in Sims 4 specifically I now have a tradition where Johnny Zest gets immediately marked as immortal whenever I start a new save because he becomes the neighborhood punching bag (thanks Vargskelethor for making this disproportionately amusing), his yard becomes the graveyard for that save, and the ghosts all get autonomous violence turned on. It's fun to sometimes just watch the ghosts fruitlessly trying to kill each other with the occasional passerby getting recruited to their ranks.