As the title sales, Steam is having a holiday sale with thousands of games being discounted, and special daily deals with extra discounts. Portal, Fallout games, Battlefield Bad Company … just a few of the heavily discounted titles available right now.

So what are you waiting for? Get your games from Steam

Alien Swarm is now a full, Source-powered 4-player co-op game (originally a UT 2004 mod), and it will be given away free on Steam on Monday (US time). All you need to do is to download the Steam software and then come back on Monday 20th July at 12pm (US PST) to get the game by going to this page.

That’s right, it’s not a typo. Save $479 (that’s four hundred and seventy nine dollars) on Steam’s Sega Complete Pack, featuring all of Sega’s best hits on Steam, including Aliens vs Predator, Empire: Total War, Football Manager 2010, Medieval II: Total War, Napoleon: Total War, Outrun 2006, Rome: Total War, SEGA Rally, Space Siege, Virtua Tennis and more, plus lots of add-on packs for all of these games. The total of the normal individual purchase prices of all of these games is $569.28, but you can get it all for only $89.99 for this week.

Get the Sega Complete Pack

The award winning Portal game is now free on Steam until the 24th of May. All you need is the free Steam application and then you’ll be able to download and install the game at absolutely no cost.

Download Portal for free here

To celebrate the launch of Civilization V soon, Steam is offering 75% off Civilization IV: The Complete Edition which features the award winning original Civilization IV, plus the Warlords and Beyond the Sword add-on packs, plus the new updated Colonization. Normally, this pack retails for $39.99, but you can get it this weekend for only $10. Or you can buy each individual title at 75% off.

Access the Civilization IV sales now

Steam is having a Codemasters racing games sale, with 5 games, including DiRT 2, reduced by 75%, with games as low as $2.50 (ToCA Racing Driver 3). Or if you buy all 5, then you can save a further $7.46 on the entire package, getting 5 racing games for $17.50.

Access the Codemasters racing games sale here

Steam is having their annual holiday sales, with some games discounted up to 80%. The current, and about to expire deals, include GTA IV for $7.49, Mirror’s Edge for $4.99, S.T.A.L.K.E.R for $1.49, and lots of other bargains.

Shop the Steam Holiday Sales

Another big discounted game at Steam, Frontlines: Fuel of War is now only $3.74, down from the original price of $14.99.

Buy Frontlines: Fuel of War

Steam is discounting the highly rated PC game Mass Effect by 50%, to only $9.99, for this weekend only. With a rating of 89 on Metacritic, it’s a fantastic game at a fantastic price.

Buy Mass Effect

Steam is having a 70% off sale for S.T.A.L.K.E.R.: Shadow of Chernobyl, making the final price only $3.75 after the discount. The game is rated 82/100 from Metacritics.

Get the game here