I agree with just about everything mentioned above. Except open world, Cast or anything else strictly from TS3. Not because I don't like those things, I just have never experienced them. They sound cool though, especially the color wheel! So many colors don't match in this game, it can be very frustrating at times.
Anyway, I think what I miss most is the little animation details. For instance:
1. Sims opening cupboards/drawers to get out a pan/pot/utencils to cook a meal.
2. Sims opening a dresser drawer before spinning around to change clothes.
3. Clocks actually showed the correct in-game time if you had one on the lot.
4. Elder Sims getting the hula girls/guys, drinks and such when they died of old age if they led a good life and/or had a platinum aspiration color from completing it. And being able to leave their loved ones an inheritance.
5. Ghosts could actually make your Sim pee their pants or scare them to death! o.O
6. Weeds growing on your lot if you didn't water the plants, ALL plants not just garden plants. It was actually worth it to hire a gardener if you had a lot of plants in TS2. I miss sprinklers too.
7. Aspiration failure animations and NPCs such as; the Social Bunny and the Doctor/Psychologist, Sims begging money on the street, putting a lampshade on their head, etc.
8. Sims stealing your newspaper (if we had them) or gnomes and putting the flaming bag of poo on your porch if they didn't like you.
9. Claire the Bear going through your trash and bunnies eating your garden veggies if you didn't fence them in.
10. All the children's interactive games like Cops & Robbers, Mary Mack, water balloon fights, etc.
And a few things already mentioned:
1. Bed animations; relaxing, making out, watching TV, reading a book, etc.
2. Doorbells!
3. Sims facing each other when they dance and especially slow dancing.
4. Food running out in the fridge and having to shop or call for home delivery.
5. Police, Firefighters and Burgler NPCs.
6. Pool tables
7. Pool toys, chaise lounges and slides.
8. Functioning cars with all their lovely animations (woo hoo, listen to stereo, joy ride, etc.) and garages, carpool, venue cabs and school bus pick-up.
9. Small telescopes - and the animation of spying on your neighbors with the possibility they might come over and yell at your Sim.
10. Using MOO to move a Sim, not just objects.
11. Couple couch animations such as; the racier making out from TS2 and Sims sitting on laps kissing, Sims having the ability to lay with their arm propped relaxing on the couch watching TV or not.
12. Swingsets, teeter totters, slides, sandboxes and toy motorized cars.
And last but certainly not least, TERRAIN/POND TOOLS, SEPARATE FOUNDATIONS and world/neighborhood decorations tools! Gah! I apologize for yelling but as a builder I miss that most of all. :)
Happy Simming y'all! <3