The U.S. video game industry continues to defy the recession, with sales in January up 13 percent compared to a year ago.

Overall January sales were $1.33 billion, up from $1.18 billion a year ago. Game hardware was up 17 percent to $445.4 million, game software grew 10 percent to $$676.6 million, and game accessories were up 11 percent to $209.8 million.

Nintendo continued to rule the roost. It sold 679,200 Wii console units, while Microsoft sold 309,000 Xbox 360s and Sony sold 203,200 PlayStation 3s. Nintendo also sold 510,800 DS handhelds, while Sony sold 172,300 PlayStation Portables and 101,200 PlayStation 2s.

Nintendo’s Wii Fit was the top-ranked game, selling 777,000 units. Nintendo also had the No. 2 game with Wii Play at 415,000 units and Mario Kart for the Wii at 292,000. Full told, it had four titles in the top ten.

Anita Frazier, an analyst at NPD, said that at this point in the console cycle (where the consoles launched in 2005 and 2006), hardware sales usually drop off and software sales pick up. It’s notable that hardware sales - thanks to the Wii - are going strong. A lot of this, as well as the top ten games list, suggests that the Wii is playing a huge role in expanding the game market to non-gamers.