Kick off the weekend by playing Booster Trooper for free! You can also save 50% purchasing a single copy or 4-pack this weekend.

Free weekend ends Sunday at 1pm (PST). 50% off sale ends Monday at 10am (PST).

Can't make it to Texas for QuakeCon this year? Or maybe you're already there, playing in the largest LAN event in North America. Either way, you can take part in the partying and fun with four days of huge sales on id and Bethesda games on Steam. Come back each day for a different deal, or just go ahead and pick up the QuakeCon Pack for about 75% off all currently available id and Bethesda games.

The QuakeCon 2010 Steam Sale kicks off today with 66% off The Elder Scrolls IV: Oblivion® Game of the Year Edition. Also at 66% off is the The Elder Scrolls IV: Oblivion® Game of the Year Edition Deluxe, which includes Knights of the Nine and the Shivering Isles expansions plus Fighter's Stronghold Expansion, Spell Tome Treasures, Vile Lair, Mehrune's Razor and much more.

Don't forget to come back tomorrow for another great deal. Offers change at 9am Pacific Time.

To celebrate the new update, Nation Red is now on sale until Thursday, August 12th, 2010.

Horde rush? Yes. Online co-op? You bet. Now's the perfect time to get yourself and your friend hooked in the all-new online co-op mode and enjoy the new weapon, perks, power-ups, and Achievements.

Puzzle Quest 2, a sequel to the award-winning, genre-defining puzzle game PuzzleQuest: Challenge of the Warlords, is now available for Pre-purchase.

Purchase between now and August 17th's launch day and save 10%!

Who needs backstory? Who needs resource-gathering? Diplomacy is so last year. Take advantage of this Gratuitous Weekend Deal and save 75% off Gratuitous Space Battles and all the Gratuitous DLC.

Gratuitous Space Battles cuts right to the chase of sci-fi strategy games, and deals with large, completely unjustified space battles between huge opposing space fleets.

Enjoy huge savings on Alien Breed during the Midweek Madness Sale! Get it at 50% off between now and Thursday, August 5th, 2010. Even better, go for the two-pack offer for an additional discount and get your friends involved in the awesome 2-player co-op mission.

For one week *all titles from Paradox Interactive will be 50% off on Steam! Experience amazing worlds with franchises like Hearts of Iron, Mount & Blade, Majesty, Europa Universalis, Lead and Gold and many more. Click here to view the complete list of Paradox titles.

*Hearts of Iron III: Semper Fi will not be on sale this week

The R.U.S.E.™ Free Preview Weekend has been extended! Keep playing now through Wednesday, July 21st at 3PM PST.

Two years ago Valve hired the talented team behind the popular top down co-op mod Alien Swarm. Since then they have been busy working on the Left 4 Dead Series, and now Portal 2. However, we never forgot about Alien Swarm and the team has spent a lot of time bringing the game to Source in between their contributions to the other Valve projects.

On Monday, July 19th Alien Swarm is going to be released for free via Steam.

In addition to the game, Valve will also release the complete code base for Alien Swarm. This includes updates to the Source engine SDK and full Steamworks integration. If you’ve ever thought about developing a mod on the Source engine with Steamworks, this release provides more insight and examples for using Steamworks in game production.

Please visit www.alienswarm.com for more information.

Join the R.U.S.E.™ Free Preview Weekend now and play a sizeable slice of the multiplayer, featuring new maps never played before. Play with 2 to 8 players, with any team or free-for-all combination, and with any of the 6 factions available in the final game.

During the Free Weekend, you can also play battles against the medium or hard AI for the first time. Select which nation your opposing AI will play and check out the strengths of each faction. Good luck defeating the hard AI!

Click here to play now for free (Requires free Steam desktop application to play. Visit www.steamgames.com/about to install Steam now.)

Free Preview Weekend ends July 18th at 1pm Pacific time.