Steam has cut 50% off its "THQ Hit Collection," offering over a dozen games for $49.99, including Company of Heroes, Homefront, Metro 2033, Red Faction Guerrilla/Armageddon and more (they're 33% off individually too). Valve's distribution channel also offers three Tomb Raider titles for 66% off and the first two Max Payne entries for 75% off. There's not a whole lot happening elsewhere, though Impulse has 50% off Call of Duty Modern Warfare and Modern Warfare 2, while Good Old Games has 50% off 20 classic Atari titles including the original Witcher.

Steam
70 Homefront $19.99 (33% off)
86 Warhammer 40,000: Dawn of War II Complete Pack $30.00 (50% off)
THQ Hit Collection $49.99 (50% off)
Max Payne Bundle $3.74 (75% off)
Tomb Raider: Anniversary $3.39 (66% off)
78  Tomb Raider: Underworld $6.79 (66% off)
Tomb Raider: Legend $5.09 (66% off)
79  Metro 2033 $13.33 (33% off)
68  Saints Row 2 $9.99 (33% off)
72  Company of Heroes Complete Pack $33.31 (33% off)
82  Supreme Commander: Forged Alliance $7.49 (50% off)
82  Darksiders $13.33 (33% off)
80  S.T.A.L.K.E.R. Bundle $23.32 (33% off)
Red Faction II $6.66 (33% off)
84  Red Faction Guerrilla $13.33 (33% off)
71 Red Faction Armageddon $33.33 (33% off)
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GamersGate
76 Men of War $3.74 (75% off)
76 Men of War: Assault Squad $8.49 (75% off)
74 Men of War: Red Tide $4.99 (75% off)
Sword of the Stars Complete Collection $4.99 (75% off)
48 Garshasp: The Monster Slayer $4.98 (50% off)
Europa Universalis III Chronicles $7.49 (75% off)
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Impulse
Call of Duty 4: Modern Warfare $9.99 (50% off)
88 Call of Duty: Modern Warfare 2 $14.99 (50% off)
61  Heroes of Might & Magic V + Tribes of the East $9.99 (50% off)
70 Homefront $14.99 (33% off -- Friday only)
67 Timeshift $8.99 (60% off -- Saturday only)
80 FIFA Soccer 10 $10.19 (66% off -- Sunday only)
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Direct2Drive
RollerCoaster Tycoon 3 Platinum $7.50 (75% off)
 Europa Universalis III Chronicles $7.50 (75% off)
Wildlife Park Tycoon $4.95 (75% off)
 Democracy 2 $5.75 (75% off)
Breaking The Rules: The Roman Tournament $2.99 (75% off)
Woodcutter Simulator 2011 $4.95 (75% off)
Snowcat Simulator $4.95 (75% off)
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Games for Windows
84 Rift $14.99 (50% off)

Good Old Games
50% off Atari Collection