I was a big big biiig fan until City Folk. I guess I played too much Wild World and City Folk was almost exactly the same game.
I think the biggest problem was actually the fact that you could import a wild world character. It meant that a lot of the collectibles, furnature, fish, bugs, ect... werent just similar to the previous game, they were exactly the same thing.
Oh and the neighbor dialog was fun but there was only enough of it for about a weeks worth of playtime, then it repeats.
....
On the other hand Swimming!