Joins Wii Play and Mario & Sonic at the Olympic Games to bring the Wii million-sellers list to four.

Mario Kart Wii screenshot

According to ELSPA, Nintendo's Wii Fit and Mario Kart Wii have each now sold over one million units in the UK, joining an elite list of titles to have reached Diamond status.

Diamond selling titles include GTA 3 (PS2), GTA: Vice City (PS2), GTA: San Andreas (PS2), The Simpsons: Hit and Run (PS2), Brain Training, New Super Mario Bros., More Brain Training, Mario & Sonic at the Olympic Games (Wii) and Wii Play.

The latest sales figures also reveal that Big Brain Academy has now sold over 600,000 units in the UK; Call of Duty: World at War (Xbox 360), Gears of War 2 and Super Smash Bros. Brawl have each reached 300,000 units sold and Fable II and Call of Duty: World at War (PS3) have sold 200,000 units.

A host of titles have also reached the 100,000 mark, including PES 2009 (Xbox 360), Fallout 3 (Xbox 360), Professor Layton, Wrath of the Lich King, Football Manager 2009 and LittleBigPlanet.