The new Animal Crossing for Wii is surprisingly fun. They really need to change up the formula at some point, but for now it's good. The addition of the city, as hyped as it was, is really nothing special.
Super Smash Bros. Brawl is fun when you can actually find someone to play it with.
A few other games I enjoyed were:
Trauma Center
Chocobo Dungeon
Zack and Wiki
NiGHTS: Journey of Dreams
At this point I wouldn't really recommend purchasing it. If they make some insane announcements in the near future, then I'd change my mind. But it seems like

would rather burn the bridge that got them to where they were. In other words, they prefer screwing over their hardcore fans just so they can make fans of the average consumer. The main problem I see with that is most of those people seem to buy the Wii, play Wii Sports and Wii Fit a bit, and shelf the system. There's no real ongoing market there.
I predict the Wii will, at some point, become the least-selling console. Not overall, but in terms of monthly sales.