Humble Double Fine Bundle
  •  currently has a bundle of Double Fine games available for PC, Mac, Linux, and Steam. You choose how much you want to pay, and the money is divided as you choose between Humble, Double Fine, and the charities Child's Play and Electronic Frontier Foundation

    You get:
    Costume Quest

    If you pay over the average (currently $6) you also get:
    Brutal Legend

    And if you pay over $16.74
    Spacebase DF-9 (early access) 

    They also have a Sid Meier bundle going on for the next 2 weeks