We talk a lot about game sales, but really nobody ever really bothers to keep track of which games have sold the most copies. Occasionally, when a big game hits you hear about "units shipped" and other assorted data, but unless you’re paying really close attention, it’s hard to keep up with who’s selling what. Forbes was curious about the greatest sellers of all time, so they enlisted the help of NPD to provide a list.

NPD searched back to 1989, though they really didn’t need to as it turns out that nearly all the games on the list are fairly recent (thus reflecting gaming’s more mainstream acceptance over the past decade). Their findings conclude that Grand Theft Auto: San Andreas is the champion, selling 9.4 million copies. Guitar Hero III: Legends of Rock pulls in at second with a respectable 8.2 million.

Of course, both those titles will be unseated by GTA IV once the dust settles, and it will likely set sales numbers unlikely to be touched in the near future.

Here’s the rest of the list, and please remember that these are U.S. sales only, so no other regions are represented. Therefore, don’t have a hissy fit that the Final Fantasy series doesn’t make a single appearance: rest assured that if we included Japan all your favorite androgynous heroes would make at least one appearance.

1. Grand Theft Auto: San Andreas
2. Guitar Hero III: Legends of Rock
3. Madden NFL 07
4. Grand Theft Auto: Vice City
5. Madden NFL 06
6. Halo 2
7. Madden NFL 08
8. Call of Duty 4: Modern Warfare
9. Grand Theft Auto 3
10. Madden NFL 05