1) Putting the babies on the floor
2) Bottles and diapers on the floor
3) Leaving dirty dishes and not being able to click on the dish to make a sim clean it up
4) Babies playing in the toilet
5) Going outside without proper clothes on, especially in colder seasons.
6) Unreasonable LTW's. (Thank God there is a mod for this) As it is now, 2 of my sims want to have 6 grandchildren so Pleasantview is gonna be filled with relatives of my first family I made when I started playing the game after reinstall. I found the mod to make the LTW's more reasonable just recently so things should be better now for future generations.
Thats all I can think of at the moment.