What are your Top 3 major updates to The Sims 4?

Hard for me to remember what features came in an update or a pack.😀

For me it would be toddlers. I still remember exactly where I was and what I was doing when toddlers were announced.

Second favorite would have to be the infant update in March 2023. 🥰

I'll have to give the third some thought.

ETA: Ok, third one is yesterday's infant & toddler update. 😄

Toddlers and Infants were very much needed 😊

b/b easy for me, stairs.

CAS I agree with OP,  Apply to Outfits

Gameplay Toddlers. 

Oh yes, the stair updates have been great over the years 😍

I can't say that I remember all of the updates specifically, and there's definitely a lot of them that had features I loved, but the three standouts that I can think of at the moment are:

~ The gender update - this unlocked all of the CAS to be able to be worn by any Sim of any gender, allowing us to use masculine clothing on female Sims and feminine hairs on male Sims, which I do all the time. I have wanted this capability since Sims 2 and it was a game changer for me.

~ The addition of the Scared emotion - I asked for that for literally years and never thought we'd get it. I love watching Sims freak out over Werewolves and ghosts and Jungle Adventure traps. I do still think it could use some tuning here and there, and was overused in some areas, underused in others, but I'm so glad we got it. The emotions were so flat and overly positive before that. It helped balance the emotional spectrum.

~ The CAS Occult overhaul. Being able to create ghosts, easily change a regular Sim into an Occult after you already made them, swapping them...and all of the eyes, teeth, face details, pointed ears, etc, that got unlocked to be able to be used on any Sim, was a giant quality of life upgrade for me. There are still a few assets that got overlooked, but the update opened up an enormous potential for being creative with making Sims, which I just love to do. 

Interesting question. I can't make up my mind and narrow it down to three. For me the best updates were

• Toddlers: the game just didn't feel complete enough without them. This was the update that made me move on from sims 2 and 3 to sims 4
• Bookends and bed upgrades: a rediculously small update but I am using these features constantly. Before this update you needed big bookcases to read, now just a few books on a desk or mantelpiece suffice. Every bed gets upgraded. It is not a major update but I want to mention it because this update is often overlooked while it really improved my game. 
• Change occult status in CAS. This used to be such a hassle before this update. 

Honorable mentions for the copy outfits in CAS, terraintools and the combination of modular stairs with platforms. 

I have a hard time remembering what added by updates and what came with packs 😁 But some good ones have been mentioned already.

The gender update was a great one. I wouldn’t have one of my favorite characters, Mimi, without that one.

The toddlers were another good one. I’m having so much fun with that one. Little Kya is a treasure.