Valve has always used the weekend to discount at least one game from their Steam service but this week it's a tad different. They are holding a massive after-Christmas sale that doesn't end until next Friday, January 2. Not only that but they are putting up every game on Steam on sale.

Yep, every game on Steam will have at least a 10 percent discount off its normal price from now until next Friday. Indeed some games and game collections will get even bigger discounts, as much as 75 percent in some cases. For example all Ubisoft games are now 25 percent off while all THQ games are between 25 to 50 percent off. All 2K Games titles are between 25 and 75 percent off. Even some of Valve's own games have huge price cuts. Counter-Strike: Source is 50 percent off, Left 4 Dead is 25 percent off, Portal is just $4.99 and Half-Life: Opposing Force and Half-Life: Blue Shift are now just 99 cents each.