1. I absolutely LOVE the toddlers! I, at times, like how independent they can be, (like how they eventually get the ability to climb stairs) but I also like how they still need help with things ( like when they are level two potty and they can try to go themselves but still need guidance from their parents and or caregivers and have the chance of having an accident).
2. CAS and how some things are, IMO, more organized than previous games. I love the idea of pushing and pulling directly on the sims.
3. The build/buy mode. I find it easier to build in this game and I love how one can utilize the Shift+Alt button to maneuver objects in spaces beyond the grid (A feature that came from 3 I believe).
4. The fact that you can search for objects in Build/Buy. I cannot tell you how freaking frustrated I am when I play 2 and 3 and I know what object I want to use but cannot find it for the life of me lol.
5. How hats are separate accessories.
6. All of the different types of foods that come from different ethnic backgrounds. So more options for all sorts of different types of restaurants.
7. Some of the things from the club system from GT. I like how you can create a club look and how sims interact with each other and others in the area based on dos and donts.
8. Though it has its issues and I wish there was also rabbit whole career attached to it, I do have a soft spot for the veterinarian career from C&D.
9. The calendar and how you can customize holidays.