After seeing tons of Sims, Warcraft and Spore games on top of these lists week after week, the latest list from the NPD Group' shows a lot of change in the top 10 best selling PC games in the US. The week that ended September 20 shows the MMO Warhammer Online on top and two other games debuting on the list.

Mythic Entertainment's long awaited MMO was expected to be on top of this week's list but the Collector's Edition was also on the list at number three. Two other titles also made the list; the budget priced first person shooter Crysis Warhead and the post-apocalpse shooter S.T.A.L.K.E.R. Clear Sky:

1. Warhammer Online - Mythic/Electronic Arts
2. Spore - Electronic Arts
3. Warhammer Online Collector's Edition - Mythic/Electronic Arts
4. Crysis Warhead - Crytek/Electronic Arts
5. The Sims 2 Apartment Life - Electronic Arts
6. Spore Galactic Edition - Electronic Arts
7. World of Warcraft - Blizzard
8. The Sims 2 Double Deluxe - Electronic Arts
9. S.T.A.L.K.E.R. Clear Sky - GSC Game World/Deep Silver
10. World of Warcraft - Blizzard