Steam's summer sale is now on. It will run until July 4th at 10am PDT (6pm UK time). A great many video games have been discounted greatly. No flash deals, no minigames, no achievements, simply a whole load of discounts. Well, and some virtual trading cards and a virtual badge you can collect through those cards. But mostly discounts!
I don't know what more you need me to say. Go on, git!