Haven't seen this excellent fitness game discussed here, so I thought I'd describe it for those who want a great workout program. It's only $30and a bargain IMO for the benefits you'll get.
GGCW is a cardio boxing game. It has tons of options for workout types, from sugggested workouts to"a la carte" exercise selections to"exams" that test accuracy of punches/footwork.
GGCW has a nice 2-wiimote control option for more accuracy than the wiimote/nunchuk combo. And there's no wires to get in the way!
The exercises are built on 3 types of punches (jab/cross, hook, and uppercut) as well as a few dodging motions. Everything is timed with a nice rhythm and selectable music (synth versions of a fw songs plus some originals?)
The workouts are great--the presentation is very engaging and before you know it, the sweat is pouring off and muscles are getting fatigued. There are many more levels of exercises (advanced combos, etc.) that I haven't tried yet, but the variety and intensity are great. One of the nice features is that every exercise set switches between regular and southpaw stances for a balanced workout on both sides.
I've tried a few exercise games on the Wii: Wii Fit, Victorious Boxers, Don King Boxing (best boxing game on the Wii yet, btw), and Outdoor Challenge. GGCW is the best intense workout so far, and is challenging enough to keep you at it for a long time. Like other games, it tracks your progress and workouts, and offers bonuses for various achievements. But the best part is the pure engagement of a hard cardio workout.