Mario Kart Wii was the top-selling game across the US, the UK and Japan during 2008, beating Wii Fit, GTA IV, Super Smash Bros. Brawl and Call of Duty: World at War.
Nintendo's racer sold 8.94 million copies last year in the three territories, shifting five million units in the US, two million in Japan and 1.94 million in the UK.
Wii Fit racked up 8.31 million sales, with a similar split between the territories.
Grand Theft Auto IV sold 7.29 million copies, with just 256,000 coming from Japan.
Super Smash Bros. Brawl sold 6.32 million units, just 404,000 of which originated in the UK.
Call Of Duty: World At War shifted 5.89 million, despite launching at the tail end of the year and not releasing in Japan.
The data comes from the latest Top Global Markets report jointly compiled by leading stat-crunchers The NPD Group, GfK Chart-Track and Enterbrain.
The groups also said that combined software unit sales across the world's three largest games markets saw growth of 11 percent in 2008, totaling 409.9 million units, compared to 367.7 million the year before.
The growth came from the US and UK, with respective increases of 15 percent and 26 percent. Japanese sales declined by 13 percent.
"UK console videogame software units are more than double what was achieved in 2003, which just shows how fast the UK market has been growing," said Dorian Bloch, GfK Chart-Track's business group director.
"Because of this amazing growth and coupled with the downtown currently being experienced in Japan, the UK market has for the first time overtaken Japan as the No2 world market. Although still behind on revenue, the gap has narrowed considerably and it will be interesting to see how things develop during 2009."