Back in the day before EA was getting voted the worst company in America, it was publishing pretty stellar PC games. Some of those games are reduced by 60% in GOG.com's weekend sale, including the Ultima, Dungeon Keeper and Wing Commander franchises, as well as Populous, Syndicate, and Theme Hospital.
If you're in the mood for some simulation gaming, then GreenManGaming has got a range of titles in its Planes, Trains, and Automobiles promo that will interest you. Highlights for me are Euro Truck Simulator 2 and Guns of Icarus Online, reduced in price by 50% and 75% respectively. If you're still in the mood for some driving, Amazon.com has a range of titles from Codemasters reduced such as DiRT 3 and F1 2012.
Steam has taken 66% off the price of a great-looking Star Wars bundle, including both Knights of the Old Republic titles, Battlefront 2, and the Jedi Knight series. Also on offer on Steam is the Tomb Raider franchise including this year's Tomb Raider reboot, yours for half price. Over on GamersGate.com, the site has got a weekend deal on Ghost Recon: Future Soldier and its accompanying DLC. If you find a great PC deal this weekend, please leave it in the comments, it's always appreciated.