The architect career: inexplicable "squalor" issues, I guess with particular households (probably because they never cleared from before, come to think of it). Also when the game stops providing jobs at all. This isn't so much an annoyance but is still technically an issue: doing the same job over and over for the same person. For instance, that Landgraab guy asked me to make him a man cave. I got to the house and found he had one. So I tweaked it and blew as much money as I could on art to use the budget. Lo and behold, he's asking for a man cave again. It's now just getting sad. I have the same with a writing room for someone, but I think that one's bugged with the "squalor" issue, so as far as the game knows, it was never done.
Firefighter: I get that the game wants you to put work in, but who designs a fire engine that runs at like half the speed of a taxi?! Also, what are all those other firefighters doing? None of them help my sims out, even on huge jobs.
Ghosthunter: I can't even play this one because it bugs out around level 2, where you have real ghosts instead of just slimers.
Not being able to re-style things like chimneys.
Stupid sims who keep trying to put the toddler to bed when he needs to go to the bathroom or eat or isn't tired. Then complains to ME for making them get up again to fix it. Hello? I'm not the stupid one here, honey.
Babysitters...why is my child starving? Why am I paying you?
Edit: Another one. I think the bands put less effort than ever into using Simlish for their songs. It's worse than Depeche Mode's effort in Sims 2, and that was pretty amusing.