WiiFit
Using its motion-detection abilities, the Wii guides you through a variety of workouts. It can rate your performance while also providing motivation through timers, music, and visual cues. Workouts range from boot-camp style drills to yoga poses.
Wii Sports
Wii Sports simulates a number of classic sporting activities such as golf, bowling, and boxing. It takes full advantage of the Wii's motion-detection capabilities and through that simulates the technical rigor required to actually score well. Because of this, you have to swing with good golf form and play tennis like a real pro.
Rock Band
Rock Band allows you experience the thrill of performing live music using video game instruments. Although it can be played on a standard controller, Rock Band can also be experienced through a variety of custom controllers--such as a microphone, gaming guitar and gaming drum set. These controllers enhance the realism of Rock Band, though even with them the game doesn't perfectly mirror real life music playing. Rather, it emphasizes timing and button pressing to the nuisances of plucking and strumming.