The people who made up the story-line for the Disney World portions of the game.
The Disney worlds I enjoyed were Space Paranoids and Timeless River. Why? Because they had to do with what was going on with the main story. Especially Space Paranoids. The worlds that involved Organization members were pretty good, I guess. But only because they gave us the impression that the story was a part of something bigger.
There wasn't a single world in Kingdom Hearts I that I didn't enjoy. It seemed as if Donald, Goofy, and Sora actually cared about THEIR quest, while still helping out the worlds. I guess the Key-Holes in each world made it seem like there was a point to the little adventures they went on.