Rayman Raving Rabbids (Wii, 2006)

All of the minigames are hilarious, and most of them are also fun to play. My two qualms are a) there is too much overlap in the gameplay of the various minigames. There are about 10 levels of on-the-rails shooter, 15 DDR-esque music play, and a bunch of distinct games where you have to pump the two controllers really fast.

The games that I loved and went back to were those that had something unique about them (for example, the game where you have to use the speaker in the wii-mote to listen to your pig that guides you through a maze; also the game of red light green light where you have to pump the controllers and then point at the middle of the screen to stop); and b) it takes quite a while to unlock the multiplayer challenges (where a bunch of minigames are strung together so that you can play multiplayer with a finite time-period in mind, as opposed to just playing random minis).

Since I bought the game almost exclusively to play with friends, it would have been nice if they had more multiplayer challenge options to begin with. All in all though, Rayman and Wii Sports have definitely satisfied my multiplayer desires at launch.