Get to Work. It was the weakest one for sure, it needs to be closer to Open for Business and less erm...well...lame. I shouldn't need to have mods to run a business out of my home, hire family members, or go grocery shopping. It really makes it hard to have an economy set up. For instance in TS2 I was able to have my farmers and fishermen set up roadside stands and tend them after a harvest. Then neighbors would all buy food from them, I could have potters, tailors, smiths, etc who all had a business connected to their homes. I could create entire economies in small villages where no one worked outside the home and everyone relied on each other (there still needed to be some gardening just in case a sim didn't visit a farmer this year). Admittedly, I have a serious issue with turning my games into long running projects and calling it "Fun" but I really miss not needing mods to create my interdependent sim villages (or at least only needing one or two).
A close second would be cats and dogs. Just because the cats and dogs should have been given their own bar (like with ts2 and 3) to be in because the mods that let you have more than 8 mess too much with CAS for me. They also should be controllable.
