Mario conquers the US, quickly leap-frogging the lifetime sales of the portly-plumber's 3D Wii outing...

Mario's latest is on a roll, and there's just no stopping. New Super Mario Bros. Wii has just passed another milestone, selling more than its bigger brother in the US.

According to official NPD figures, New Super Mario Bros. Wii sold 4.2 million units in 45 days - from its launch in November through to the end of December. In comparison, Super Mario Galaxy - having launched in November 2007 - had amassed sales of 4.1 million units by the end of 2009.

Debates on which title is more 'deserving' of the success will likely rage on in murky internet boards, but one thing remains clear - with Galaxy 2 just around the corner, the Mario juggernaut seems to be healthier now than its ever been.