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

For Game Pack, it's Dine Out by some margin. If you want to sell food, do it on a basic retail lot, or in a cafe. Dine Out's restaraunts are so full of bugs, and managing one is a nightmare.

For Expansion, this is harder but I'm gonna have to go with Island Living. I love Sulani, but Island Living feels like a glorified Game Pack. Many of its features (Mermaids, Island Spirits, the tepid lot traits, ocean swimming) are underdeveloped. I understand that it's a more culturally themed back, and so hotels and the like weren't ever going to come, but at least go full force with the cultural aspects. Give me more interesting Island Spirits, make the volcano dangerous, give me Haka.