If this week's breakdown of the best-selling titles from digital distribution outlets Steam and Direct2Drive looks a bit familiar, that's probably because you saw last week and for the most part, the week before that.

There are some subtle differences; the THQ Collector Pack and Call of Duty 4 weren't on last week's Steam list, CoD: World at War and The Witcher are new to this week's Direct2Drive chart -- but mostly, it's the same stuff in a slightly different order with some of the preorders doing quite well.

Steam's Top Ten (by Revenue) (8/23 - 8/29)

1. Left 4 Dead / Valve
2. Aion Collector's Edition (pre-order) / NCsoft
3. THQ Collector Pack
4. Counter-Strike: Source / Valve
5. Killing Floor / Tripwire
6. Team Fortress 2 / Valve
7. The Orange Box / Valve
8. Fallout Collection (F1, F2, Fallout Tactics)
9. Call of Duty 4: Modern Warfare / Infinity Ward
10. Valve Complete Pack / Valve

More after the break...

Direct2Drive's Top Ten (8/23 - 8/29)

1. Champions Online (pre-order) / Cryptic
2. Fallen Earth (pre-order) / Fallen Earth, Icarus Studios
3. Aion Collector's Edition (pre-order) / NCSoft
4. Rise of Flight / neoqb
5. Fallout 3 / Bethesda Softworks
6. Hearts of Iron III / Paradox Interactive
7. Civilization 4: The Complete Edition / Firaxis
8. Call of Duty: World at War / Treyarch
9. The Sims 3 / The Sims Studio
10. The Witcher: Enhanced Edition - Director's Cut / CD Projekt RED