http://kotaku.com/5014253/top-us+selling -games-of-all-time-violence-and-football
Those to lazy to click the link here's the top 10 games sold in the U.S.A alone since 1989.
1. Grand Theft Auto: San Andreas
2. Guitar Hero III
3. Madden 07
4. Grand Theft Auto: Vice City
5. Madden 06
6. Halo 2
7. Madden 08
8. Call of Duty 4
9. Grand Theft Auto 3
10. Madden 05
Despite being American myself, they're fucking stupid for buying Madden Games every year. They need to stop. Also San Andreas sucked, that game shouldn't have sold that much.
Stupid Americans.
In all honesty. The best selling game of all time (that isn't packaged with a console) is Pokemon Red & Blue but that's all over the world not just the U.S.