The Seasons for the EP. It's a real game changer. Just imagine having a world that changes every season, except Oasis Spring, if you have the base game only.
Parenthood for the GP. This is actually one of the best packs. If you enjoy the generational play, this pack comes with additional trait that will help your Sims in the future.
Tiny Living for the SP. This is a great addition to the game. It allows the Sims to living large in a small space.
Then again, I don't know your play style, but this is going to be my choice if I have to choose one each.
