Earlier model Wii's also have backwards compatability with Gamecube, so all you need is the games and controllers if you already have one of those. Not sure if that's going to see many more updates.
Though not a party game as such I'd recommend buying Jungle Beat and a pair of bongo controllers if you do go down the Gamecube route.
Though not a party game as such I'd recommend buying Jungle Beat and a pair of bongo controllers if you do go down the Gamecube route.