For me, my performance problems are #1 (everything taking forever and occasional crashes). Then the bugged paranormal career--a whole job my Sims can never have. And the bugged architecture-car issue.
Beyond that, the game waking them up too late in the morning, the firefighters taking upwards of 2 hours to respond to a disaster (but I know that's "game time," which is minutes--it just looks silly when the day's half over by the time they get there), my sims reading all the time and carrying multiples of the *same book* in their inventory, the kids' TV sounds, the issue of having to be on the lot for a photo to take in the architecture career (which is an even bigger issue when her son's off fighting a fire, so I have two to manage at once), the hairstyles, the picking up food to eat and not eating it, the limited recipe options, and the difficulties replacing books on shelves (unless I'm missing something). Also, I think my maid doesn't show up sometimes.
And why is it that one of my sims is in town, he just reads a book instead of talking to people? There's something so unwholesome about a teenager sitting in a park at 11 pm, reading a children's book.