Valve is celebrating conventions such as PAX East and the Independent Games Festival with a promotion that offers various discounts across Steam's indie catalog, much of which is reduced by 50% or more. In addition to the indie event, Steam cuts half off Dark Souls and Natural Selection along with a free access weekend on the latter. Meanwhile, Amazon has a pack of more than three dozen classic Sega Genesis titles for $7.49, GameFly's spring sale knocks 60-75% off Borderlands 2, Dishonored, Syndicate and GTA IV, and Origin's "player appreciation sale" serves up half off on Crysis 3, BF3, Dead Space 3 and more.

Steam
85  Dark Souls: Prepare to Die Edition $19.99 (50% off)
82  Natural Selection 2 $12.49 (50% off + free weekend)
87 Antichamber $11.99 (40% off)
85 Terraria $2.49 (75% off)
88 FTL: Faster Than Light $4.99 (50% off)
83 AudioSurf $2.49 (75% off)
85 Trine Complete Collection $7.49 (75% off)
78  Capsized $2.99 (70% off)
86  Frozen Synapse: Complete Pack $8.74 ((75% off)
82  To the Moon $3.99 (60% off)
Commandos Collection $3.74 (75% off)
Puddle $2.99 (70% off)
Euro Truck Simulator $19.99 (50% off)
Retro City Rampage $4.99 (67% off)
Miasmata $7.49 (50% off)
Postal 2 Complete $5.09 (66% off)
Kentucky Route Zero $18.74 (25% off)
Garry's Mod $2.49 (75% off)
Hotline Miami $4.99 (50% off)
Magical Drop V $2.49 (75% off)
Giana Sisters: Twisted Dreams $7.49 (50% off)
Unmechanical $2.49 (75% off)
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Amazon Digital
64  Binary Domain $4.99 (80% off)
73  Blood Bowl Legendary Edition $5.99 (70% off)
87  Warhammer 40,000: Dawn of War Platinum Edition $9.99 (67% off)
86  Warhammer 40,000: Dawn of War II Gold Edition $9.99 (67% off)
75  Warhammer 40,000: Space Marine $18.39 (39% off)
Sega 90's Classic Pack $4.99 (83% off)
Sega Genesis Classic Game Pack $7.49 (80% off)
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GameStop
73 Cities in Motion Collection $24.99 (50% off)
Fable - The Lost Chapters $4.99 (50% off)
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GamersGate
82 Just Cause 2 Complete Edition $7.50 (75% off)
72  The Cave $7.50 (50% off)
85  Europa Universalis Collection $20.00 (75% off)
Galaxy on Fire 2 Full HD $5.00 (75% off)
Inversion $19.95 (50% off)
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GameFly
87 Borderlands 2 $20.40 (66% off)
91 Dishonored $23.99 (60% off)
74 Syndicate $4.99 (75% off)
87 Assassin's Creed III $34.99 (30% off)
88 Grand Theft Auto IV: Complete Edition $7.49 (75% off)
F1 2012 $15.99 (60% off)
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Green Man Gaming
42 Aliens vs Predator $3.74 (75% off)
64 Alpha Protocol $3.74 (75% off)
72  Virtua Tennis 4 $3.74 (75% off)
75  Doom 3 BFG Edition $14.99 (50% off)
70  Sacred 2: Gold Edition $6.79 (66% off)
Spellforce: Platinum Edition $2.49 (75% off)
Hell Yeah! Complete Pack $5.86 (75% off)
Arcania $4.99 (75% off)
~75% off Total War titles
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Get Games
80 Sleeping Dogs Limited Edition $12.49 (75% off)
82 Lara Croft and the Guardian of Light $3.74 (75% off)
78 Tomb Raider: Underworld $3.74 (75% off)
78 Tomb Raider Anniversary $3.74 (75% off)
82 Tomb Raider: Legend $2.49 (75% off)
88 Tomb Raider $39.99 (20% off)
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Origin
78 Crysis 3 $29.99 (50% off)
92 The Walking Dead $10.00 (60% off)
88 Battlefield 3 Premium Edition $29.99 (50% off)
78 Dead Space 3 $29.99 (50% off)
87 Mass Effect 3 $9.99 (50% off)
79 Hitman: Absolution $15.00 (63% off)
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GOG
60% off Atari titles