I'd recommend you watch this video to help:
https://www.youtube.com/watch?v=4RKT4UbSRuQ
It's all opinion, but he really explains the pros and cons of each pack, and it's based on a player survey.
Here's my personal opinions. I'd consider myself more of a builder than a live mode player, so a lot of this is based on build/buy and CAS items. After all, this is a STUFF pack right?
1. Laundry Day is the #1 best pack. The gameplay is realistic and I use ALL of the items regularly (which is more than I can say about ANY other pack... GPs and EPs included). The clothing and hair is nice. It's just an all-around awesome pack.
2. You might also consider Perfect Patio because you might be able to put a hot tub in your apartment (depending on the style), and it does come with some nice wicker furniture.
3. I don't personally have Movie Hangout but I've been wanting it because it does have SOME cool decorations. It's a very specific style, though, so check it out to make sure it's your thing before you invest.
What NOT to buy:
1. Cool Kitchen stuff was a huge disappointment. I rarely use anything from that pack.
2. Spooky Stuff is just a whole bunch of Halloween costumes. Cool for Halloween, but not worth $10. Only thing I really like from that pack is the pumpkin carving.
3. Fitness Stuff comes with some cool-looking workout equipment, but it's all interactions you can do with base game. There's a serious lack of new furniture/decor with this pack. Only thing I really like is the new workout clothing.
4. I'm not a fan of Bowling Night, even though I like retro items. But these items seem very "commercial". Not things that easily fit into a residential lot. I WILL say, though, that the bowling interactions are cool. Just not my thing, I guess.
I left a few off this list because I just don't think they're what you're interested in.