If you've missed the zillion chances to grab Deus Ex on sale, Steam is offering another opportunity with 75% off the entire franchise, including Human Revolution and its downloadable content. Things are relatively quiet elsewhere as GameStop continues to offer 50-75% off Assassin's Creed titles, GamersGate has substantial savings on Hard Reset and Total War games, GOG lets you vote for discounts, and Origin knocks 50% off select titles if you preorder another game.

Steam
87 Deus Ex Collection $14.99 (75% off)
50 Post Apocalyptic Mayhem $2.49 (75% off)
Cubemen $1.99 (60% off)
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Amazon Digital
88 Super Street Fighter IV: Arcade Edition $9.99 (75% off)
90 Mass Effect $4.99 (75% off)
93 Mass Effect 2 $4.99 (75% off)
69 Payday: The Heist $9.99 (50% off)
78 Tropico 4 $19.99 (50% off) 
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GameStop
78 Darksiders $4.99 (75% off)
83 Saints Row: The Third $16.99 (66% off)
74 Assassin's Creed $4.99 (75% off)
89 Assassin's Creed 2 $9.99 (50% off)
88 Assassin's Creed: Brotherhood $14.99 (50% off)
67 Aliens vs. Predator $7.49 (50% off)
BioShock $9.99 (50% off)
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GamersGate
68 Need for Speed: The Run $15.98 (60% off)
85 Amnesia: The Dark Descent $4.95 (75% off)
88 Total War: Shogun 2 $7.49 (75% off) 
82 Empire & Napoleon Total War GotY $8.99 (70% off)
83 Orcs Must Die! $7.50 (50% off)
85 Jamestown: The Legend of the Lost Colony $4.98 (50% off)
73 Hard Reset $6.80 (66% off)
Rome: Total War Complete $3.74 (75% off)
Medieval 2 Total War Gold Edition $2.49 (75% off)
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GOG
Gothic $4.99 (40% off)
Arx Fatalis $2.39 (60% off)
Vote on tomorrow's deals

GameFly
69 Payday: The Heist $9.99 (50% off)

Green Man Gaming
Up to 50% off Iceberg Interactive titles

Games for Windows
{pf id: size:small} Battlefield: Bad Company 2 $9.99 (50% off)

Origin
Preorder a game, get another half off