Due to the strong performance of Steam and Impulse's various exclusive games, there's no clear winner, so to speak--every outlet has an entirely different top five, with BioShock 2 and Mass Effect 2 marking the only two titles to appear on more than one list.

Update: There is a clear winner after all--in the form of Battlefield: Bad Company 2--one that was temporarily obscured as Steam seemingly removes pre-orders from its "Weekly Top Sellers" RSS after a game is released, as BFBC2 and SupCom 2 were this Tuesday. Thankfully, Blue's News archived the initial listing on Monday.

Steam (By Revenue) - February 21 through February 27, 2010
1. Battlefield: Bad Company 2 LE (Pre-Order) - DICE
2. *Supreme Commander 2 - Gas Powered Games
3. *Call of Duty: Modern Warfare 2 - Infinity Ward
4. *Napoleon: Total War Imperial Edition - Creative Assembly
5. *Aliens vs. Predator - Rebellion
6. *Napoleon: Total War - Creative Assembly
7. Assassin's Creed 2 (Pre-Order) - Ubisoft Montreal
8. SpellForce 2: Gold Edition - Phenomic
9. Dawn of War II - Chaos Rising (Pre-Order) - Relic
10. BioShock 2 - 2K Marin, Digital Extremes
11. *Left 4 Dead 2 - Valve
12. Mass Effect 2 - BioWare

Direct2Drive - February 21 through February 27, 2010
1. Battlefield: Bad Company 2 LE (Pre-Order) - EA DICE
2. Star Trek Online Digital Deluxe Edition - Cryptic
3. BioShock 1 + 2 Bundle - 2K Games
4. Star Trek Online - Cryptic
5. Dragon Age: Origins + Awakening Pre-Order Bundle - BioWare
6. Civilization 4 Complete - Firaxis
7. Aion - NCSoft
8. Mass Effect 2 Digital Deluxe Edition - BioWare
9. BioShock 2 - 2K Marin, Digital Extremes
10. Mass Effect 2 - BioWare

Impulse - February 21 through February 27, 2010
1. *Sins of a Solar Empire Trinity Pack - Ironclad
2. *Sins of a Solar Empire: Diplomacy - Ironclad
3. *Sins of a Solar Empire Expansion Bundle - Ironclad
4. Dawn of Discovery Gold - Blue Byte
5. Mount & Blade - Taleworlds
6. *GalCiv II: Ultimate Edition - Stardock
7. *Sins of a Solar Empire: Entrenchment - Ironclad
8. Ecochron Legends - StarWrath3D
9. Eufloria - Omni-Labs
10. Supreme Commander Gold - Gas Powered Games

* Denotes a title exclusive to the digital distribution outlet