I like to play flexibly so a numeric ranking is more of an approximation than a strict ranking but ok, sure, I play with different themes and with few regrets.
Favorites:
1. Parenthood with Growing Together - This does make families a lot more interesting and replayable. Families form the basis of a lot of my playstyle with a rotational legacy but then I change things up with fun activities.
2. Dine Out and Spa Day - I use both of these a lot for regular gameplay all the time. I've read a review that some players don't need a playable spa but this pack added a lot to my game. My sims like to bliss out and I like the detail in the yoga. I even appreciated the refresh with painting nails. I have numerous restaurants and several spas, I could see adding more. Dine Out has occasionally required bug fixes but I have it working now with Get Famous.
3. Jungle Adventure - I love the travel packs and this one is really fun. I ranked some packs I use more often slightly above it but I'm glad to have it. I've been to the region that it's about and it feels authentic. Very fun.
4. Strangerville - This was a hit for me and I have continued using the world a lot because I love the atmosphere. I like that they let you decide what to do with the world afterwards. I kept it as "normal" but it is a quirky small town that I play with.
5. Dream Home Decorator - I do like this pack, I use the CAS/BB a lot and I have a few competing decorators in my game. I've made some quirky interior design with this pack. I had never seen so much cosmolux before, lol, but now one of my houses is a swinging 60's mansion. Fun to play.
6. My Wedding Stories - Tartosa is a setting I really wanted in my game. I've just lightly used this pack so far but I've been getting the hang of it and I do understand it. I will keep using it and Tartosa is definitely a place I'll enjoy with Sims.
7. Vampires - I only have a few vampires but this is a great pack. I appreciate the Victorian decor that I use elsewhere. I do have the vampires in my game but I restrict them to just a few. They are very detailed and it's a great pack for occult play.
8. Outdoor Retreat - I do actually use this camping site especially for family-friendly trips or for sims who just want time outdoors in the woods. I've played with most of the features in it and I enjoy it. It would be great if they would add swimming in this world.
9. Realm of Magic - I'm not an occult player.
10. Journey to Batuu - It's not entirely my style of play but I have played with it and probably will again at some point. I'm glad that it exists for people who really want that playstyle.
11. Werewolves - I have not played with this one and it is not really my style. The world does interest me but the theme and the CAS/BB aren't really my thing. I do appreciate that we have the option to restrict werewolf play to just Moonwood Mill. It's possible that I'll play this a bit at some point.
I realize that my list is not everyone else's list. Honestly, I enjoy just about all of what I have. I don't mind that they make occult content at all, I'm just a very occasional player with that stuff whereas I play a lot with a more realistic but not boring style. A lot of the list is almost tied for me.