What pack(s) should I score today?

I'd buy Realm of Magic to be honest, but that's just my own biased opinion :D however, Outdoor Retreat would be great as well if you just want it for the plants, because the whole pack has basically no other gameplay besides the herbalism skill. Also, since you have seasons, it'll probably rain a lot in Granite Falls from my experience at least. StrangerVille can be fun as well, though doesn't have any replayability and you can't play the town normally without completing the story first (unless you use mods). The stuff packs are all basically useless, I still don't know why I even wanted any of them. Out of those you've listed however, I'd buy laundry day simply because it got some great bb stuff. Don't expect too much from the gameplay aspect though. I prefer TS3s laundry, which was just a side feature in two expansions, over TS4s laundry any day.
Just don't buy My First Pet unless it's on sale for like 2$. Anything else would be a huge rip off.