In the 16 months since Wii Fit was released, Nintendo's unexpectedly huge hit has rarely been out of the top 10

sellers. In fact, VG Chartz has it as the No. 8 seller worldwide this week, and the NPD Group said the game/interactive workout sold 128,000 copies just in August in the United States. We're talking an estimated 22 million copies sold worldwide since May 2008. Now, that's a workout.
Joining the Wii exercise routine Sunday is Wii Fit Plus. I can't really say that it's long-awaited. The update is merely variations on a theme, with three new strength-training exercises and yoga activities, and 15 balance games. Oh, yeah -- you can also track your dog's or cat's weight and create an avatar for your pet. ( I know a lardy beagle, pictured, who could use a bit of a workout.) But Wii Fit Plus has a huge advantage over its popular predecessor: It's available in a disc-only version, for a paltry $20, in addition to coming in a bundle with the Balance Board ($90). Wii Fit only came in the expensive bundle form. And that's why the disc-only Wii Fit Plus is currently the No. 3 game on Amazon's bestsellers list.