Wii Fit is on the verge of becoming the second-highest selling "game" in the US of the last 10 years. IGN reports on NPD data, revealing that Wii Fit has reached 7.9 million sales, passing by Grand Theft Auto: Vice City's 6.9 million and creeping up quickly on Grand Theft Auto: San Andreas' 8.25 million units. The only thing ready to kill Wii Fit's momentum is Wii Fit Plus, which will replace the previous version at retail.Some out there are probably ready to argue that Wii Fit should not be counted among other games. Yeah, those folks are going to pitch a fit about the top seller: Wii Play. The controller-bundled "software" holds the crown, having reached 11.1 million sales. We can't wait to see how the Vitality Sensor does.Gallery: Wii Fit