As expected, Valve and its cohorts have prepared a veritable pantheon of game deals for the holidays. We've included a list of Steam's notable daily deals, which will be replaced tomorrow morning with a fresh set of mega-sales. If you'd rather not wait for titles to appear on the front page, you'll find hundreds of static discounts via the Holiday Bundle Packs and Publisher Catalogs. Naturally, GamersGate, GameStop, Good Old Games and others have joined the merriments with their own promotional offerings.

Steam
76 Rage $14.99 (50% off)
83 Saints Row: The Third $33.49 (33% off)
86 Dirt 3 $16.99 (66% off)
77 From Dust $7.49 (50% off)
67 Aliens vs. Predator $3.99 (80% off)
77 Back to the Future: The Game $9.99 (60% off)
75 Railworks 3: Train Simulator 2012 $3.49 (90% off) 
83 AudioSurf $2.49 (75% off)
86 Frozen Synapse $3.74 (75% off)
65 Cities XL 2012 $19.99 (50% off)
E.Y.E Divine Cybermancy $2.49 (75% off)
Holiday Bundle Packs
Publisher Catalogs
More...

GamersGate
67  Need for Speed: The Run $29.95 (40% off)
87  Sid Meier's Civilization V $10.18 (66% off)
79  Metro 2033 $9.98 (50% off)
82  Just Cause 2 $11.97 (40% off)
88  Grand Theft Auto Complete $24.98 (50% off)
88  Total War Shogun 2 $14.98 (50% off)
82  Empire & Napoleon Total War $14.98 (50% off)
82  Dungeon Defenders $7.50 (50% off)
87  Deus Ex: Human Revolution $16.98 (66% off)
75  Two Worlds 2 $14.98 (50% off)
75  Magicka $3.40 (66% off)
74  Dead Island $26.77 (33% off)
Call of Duty 4: Modern Warfare $19.98 (50% off)
More...

GameStop
83 Crysis Bundle $43.97 (60% off)
84 Resident Evil 5 $9.99 (50% off)
90 Street Fighter IV $4.99 (75% off)
90 Dragon Age Bundle $23.97 (60% off)
90 Plants vs. Zombies GotY $4.97 (50% off)
82 Mafia II $7.49 (75% off)
60 Dark Void $2.99 (75% off)
67 Dungeon Siege III $24.99 (50% off)
82 L.A. Noire: The Compete Edition $33.49 (33% off)
89 Dead Space Bundle $19.99 (60% off)
Grand Theft Auto IV $4.99 (75% off)
Grand Theft Auto: San Andreas $3.74 (75% off)
Grand Theft Auto: Vice City $2.49 (75% off)
More...

Direct2Drive
71 Nuclear Dawn $12.50 (50% off)
78 Dragon Age II $4.95 (75% off)
74 Dark Fall: Lost Souls $6.50 (35% off)
73 Buy Cities in Motion get six DLC packs free $19.95
Baron Wittard: Nemesis of Ragnarok $4.95 (50% off)
More...

Origin
89 Dead Space 2 $9.99 (50% off)
90 Dragon Age Origins Ultimate Edition $9.99 (66% off)
79 Need for Speed: Shift 2 - Unleashed $9.99 (50% off)
81 Bulletstorm $9.99 (50% off)
SimCity 4 Deluxe Edition $9.99 (50% off)
The SimCity Box $9.99 (50% off)
More...

Good Old Games
50% off most titles