The NPD Group released the September PC sales data for North American retailers yesterday. Aion and Champions Online, the two MMO's debuting during the month, both made a good showing. Which one beat the other, though?

1. Aion - NCsoft
2. The Sims 3 - Electronic Arts
3. Champions Online - Atari
4. World Of Warcraft: Wrath Of The Lich King - Blizzard
5. Aion Collector's Edition - NCsoft
6. Mumbo Jumbo Assortment - Mumbo Jumbo
7. The Sims 2 Double Deluxe - Electronic Arts
8. World Of Warcraft: Battle Chest - Blizzard
9. Reel Deal Slots Treasures Of The Far East - Phantom EFX
10. World Of Warcraft - Blizzard
11. Spore - Electronic Arts
12. Grand Theft Auto IV - Take-Two
13. Starcraft: Battle Chest - Blizzard
14. Zuma's Revenge - PopCap
15. World Of Warcraft: Burning Crusade - Blizzard
16. Batman: Arkham Asylum - Square Enix
17. Reel Deal Slots Adventure - Phantom EFX
18. Nancy Drew: Ransom Of The Seven Ships - Her Interactive
19. Civilization IV: Complete Edition - Take-Two
20. The Sims 2 University Life Collection - Electronic Arts

Champions launched on September 1st, giving it a three-week lead on Aion but apparently that wasn't enough to topple NCSoft's medieval fantasy MMO. Note that this data doesn't include digital sales (through Steam or similar online retailers) so there's a limit to its accuracy. Also, the exact number of units sold isn't revealed here.

Good to see both MMO's selling strong on launch, but what really matters is how many of their players will still be with the game over the months to come. A lot of the players on both games are likely World of Warcraft players looking for a change of pace (such has been my experience with Aion anyway) and many of them may creep back to WoW if they get bored/frustrated with their new game.