I would recommend Seasons and City Living. Those were first I bought after playing for some time with just base game and even today I think it was a good decision.
Seasons adds changing of weather, temperature effects and holidays which is something that I couldn’t play without. It’s one step closer to more realistic gameplay, even when someone plays in hot worlds like Oasis Springs, there will be periods of heat weaves that makes sims miserable.
City Living because it adds big city and real apartments. Many worlds in Sims 4 has a skyscraper landscape in the distance and sims inhabit only the suburb part of the world. City Living add those skyscrapers to the game and makes them usable plus a taste of living a little bit different lifestyle than in suburban family house. On top of that you get karaoke bars, festivals, ability to be street musician etc.
Those two packs may have some weak points and could be done better, but in my opinion they expand the game and its world by adding something truest different.
I don’t recommend Get Together for new players because Windenburg while gorgeous and big, is not that much different from other worlds. Sure it has German style to it, but it’s nowhere near big metropolis. Club system depends strongly on how person plays. I myself rarely use this feature, maybe because there is a bug that makes the bored moodlet stay even after sim is no longer club member heh. But bugs aside, my sims are usually lone wolfs or have close knit life style so they don’t need big gatherings. This is how I play most of my families and clubs are not very useful in this case.
