What's the worst expansion pack and game pack and why?

Island Living was kind of disappointing to me, but it's okay. I wanted resorts, but that's okay. The dev team still added some really cool objects to the game with that EP, though. Don't really care about the mermaids, so I'm not even going to comment on that.

Spa Day might be my least favorite GP, but only because I rarely use the spa. Maybe I'll change my mind if I try building one? I love the objects that came with this pack, but game play was kind of blah. Owning and operating a spa would be something I'd love to have in this pack.