There's a few that annoy me the most. Of course I downloaded stopper mods for most of them, thankfully.
-Anything that has to do with Babies and Toddlers. Just leave them alone for three seconds so I can take care of them with one Sim, like I intended!
-Kids and Teens going ballistic when they get an A+. The first time's understandable, the second, third, fourth, fifth, and sixth are not.
-Neighbors insisting that they can use everything in your house. No, you cannot play SSX 3 on my computer. No, you cannot watch the TV in my kid's room. No, you cannot turn on the radio and leave it so that my Sims moan about it when I send them to bed.
-Guests staying in the Hot Tub long after your Sims have gone to bed. The only way that you can kick them out is by doing Say Goodbye/Ask To Leave to all guests. Even when everyone else leaves, those people in the Hot Tub are just chillin' away.
-Employees leaving their job to do something. This happened to me when I had a Sim enter a dance contest downtown and then I saw the Host leave his station (with customers, mind you!) to join the dance contest. Needless to say I fired him immediately.