Things you (the player) do that probably annoys your sims.

For me, I think it's got to be "giving them leftovers from the same meal until it either spoils or they run out" at which time I usually try to let them make something different...and then make them eat that until it spoils lol.

Also, making new sims and then abandoning them to play with the same sims who've been in my game for three years.