Topping Steam's recent discount, Get Games offers Borderlands 2 for only $23.99, which might be the cheapest we've seen it outside of services like CDKeysHere, as well as 50% off The Cave, Double Fine's recently released adventure title. Other noteworthy mentions include half off Natural Selection 2 and free access to War of the Roses at Steam, a Batman Arkham Collection for $22.48 at GamersGate, MoH: Warfighter for $14.99 at GameFly, and a Sleeping Dogs Bundle for $25.81 at Green Man Gaming.

Steam
90 Mark of the Ninja $4.99 (67% off)
78 Capsized $2.49 (75% off)
62 Space Empires IV and V Pack $4.99 (75% off)
74 Section 8: Prejudice $5.09 (66% off)
58 Gemini Wars $6.79 (66% off)
War of the Roses $4.99 (75% off + free weekend)
Natural Selection 2 $12.49 (50% off)
Stellar Impact Bundle $2.99 (75% off)
Cave Story+ $2.50 (75% off -- today only)
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Amazon Digital
76 Wallace & Gromit's Bundle $9.49 (73% off)
78 Poker Night at the Inventory $2.49 (50% off)
War of the Human Tanks $4.99 (50% off)
Farming Simulator 2013 $18.99 (37% off)
Talisman Prologue $4.99 (50% off)
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GameStop
73 Warlock: Master of the Arcane Bundle $14.99 (50% off)
75 Magicka Collection $9.99 (50% off)
79 R.U.S.E. $9.99 (50% off)
43 Sword of the Stars Complete $4.99 (50% off)
76 Hearts of Iron III Collection $14.99 (50% off)
81 Europa Universalis III Complete $7.49 (50% off)
70 Mount & Blade: With Fire & Sword $4.99 (50% off)
73 Cities in Motion Collection $24.99 (50% off)
Fort Zombie $4.99 (50% off)
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GamersGate
85 Dirt 2 $10.02 (33% off)
89 Batman Arkham Collection $22.48 (50% off)
84  Lego Batman $9.98 (50% off)
82 Lego Batman 2 $15.00 (70% off)
60 Front Mission Evolved $4.99 (75% off)
75 Two Worlds Complete Collection $14.99 (70% off)
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GameFly
83 Alan Wake $7.49 (75% off)
77 The Darkness II $7.49 (75% off)
57 Medal of Honor: Warfighter $14.99 (50% off)
71 Nuclear Dawn $4.49 (75% off)
35 Postal III $3.75 (75% off)
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Green Man Gaming
80 Sleeping Dogs Bundle $25.81 (66% off)
82 Chivalry: Medieval Warfare $12.49 (50% off)
76 The Last Remnant $3.74 (75% off)
83 Sonic the Hedgehog Bundle $26.95 (75% off)
82  Tomb Raider Collection $29.99 (50% off)
Sega Retro Bundle $21.08 (75% off)
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Get Games
87  Borderlands 2 $23.99 (60% off)
64 Binary Domain $6.24 (75% off)
64 Alpha Protocol $3.74 (75% off)
67 Aliens vs. Predator $3.74 (75% off)
82 Just Cause 2 $3.74 (75% off)
81 Splinter Cell: Conviction $6.79 (66% off)
74 Unstoppable Gorg $2.49 (75% off)
72 Virtua Tennis 4 $3.74 (75% off)
Shoot Many Robots $3.99 (60% off)
The Cave $7.49 (50% off)
Hell Yeah: Wrath of the Dead Rabbit $3.74 (75% off)
Sine Mora $6.99 (53% off)
Viking: Battle for Asgard $3.74 (75% off)
Scary Girl $5.19 (60% off)
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GOG
50% off Daedalic titles