I'm USUALLY nice to the sims and play normally. But I have one sim who lures others sims into moving in with him and then kills them. And I play one house with my friend and his ex who are married but the ex sleeps around when he's not home.
And sometimes I make houses of people I don't like and keep one major item out of their house. like a bed or fridge or toilet and just let them run on their own till I get bored of them and kill them.
I miss the sims-on-a-stick death stuff for the sims 1. The electric shower was wonderful. I'd line up about 4 showers and one would be an electirc shower and then just let them pick a shower themselves. That was always a good time.