With Mass Effect 3 shipping more than three and half million units during its launch month, it's no surprise that its commercial success has resulted in the game leading software sales in the US and UK.During Nintendo's financial briefing for investors, the company showcased both Chart-Track and NPD data for 2012's best-selling games thus far. In it, Mass Effect 3 triumphed with BioWare's action role-playing game being the best-selling title in both the United States and United Kingdom throughout the first three months of 2012.Within America,took first place ahead of Ubisoft's Just Dance 3 for Wii, followed by Call of Duty: Modern Warfare 3 for Xbox 360, NBA 2K12, andfor the PlayStation 3.In Europe, second place was. Just Dance 3 for Wii came in third, followed by FIFA Street andBattlefield 3.It's worth noting the difference between shipping copies and selling them, though. Over 3.5 million copies were shipped but the amount actually sold during March hovered around a million.