Only one thing? Thats hard, but i'll try ;)
GTW: Active Firefighter Career
Get Together: illuminated Disco Ball
Seasons: Kite Flying
Cats & Dogs: Chicken Coop
Parenthood: Active Daycare Career
Get Famous: More Lots
Island Living: Ownable Resorts
Patio Stuff: Pool Bar
Kids Room Stuff: Bunk Beds
Vintage Glamour: Grand (curved) Staircase
Luxury Party: craftable Ice Statues (maybe as active Sculptor Career?)
Romantic Garden Stuff: Slow Dance together
Spooky Stuff: Conjurable Zombies (so nobody has to deal with them if they don't want to)
Backyard Stuff: a Tree where you can build a Treehouse for Kids
Movie Hangout: Cinema Lot where everybody sits down and shuts up. ;)
Cool Kitchen Stuff: Under Counter Fridge
Fitness Stuff: Exercise Bikes (yay spinning classes!)
Bowling Night: Pinball Machine
Toddler Stuff: Imaginary Friend Trait (So it's optional - And please a less creepy one)
Outdoor Retreat: Storymode like Strangerville, but about the mystery to become a Werewolf or get cured again.
Dine Out: Being the Cook in the own Restaurant
Vampires: More Lots
Spa Day: Owning a and working in the own Spa
Jungle Adventures: mazes in the temples like in Sims 3
StrangerVille: Story Arch to become a Plant Sim (a real one. Not those green colored excuses.)
Laundry Day: Under Counter Washers/Dryers