The latest word from sales-tracking companies NPD, Chart-Track and Enterbrain is that Grand Theft Auto IV, Super Smash Bros Brawl and Mario Kart Wii are the three top sellers in 2008 (so far, that is).

They plan to release a monthly Top Global Markets Report, detailing retail game sales across the US, UK and Japan. Here’s a sample from the first report, which uncovers game salers from January to July this year:

1. Grand Theft Auto IV (PS3, 360) - 6.29M (4.71M US, 1.58M UK, Not yet released in Japan)
2. Super Smash Bros Brawl (Wii) - 5.43M (3.53M US, 213K UK, 1.68M Japan)
3. Mario Kart Wii (Wii) - 4.69M (2.4M US, 687K UK, 1.6M Japan)
4. Wii Fit (Wii) - 3.6M (1.43M US, 624K UK, 1.54M Japan)
5. Guitar Hero III: Legends of Rock - 3.47M (3.03M US, 412K UK, 26K Japan)