Double Fine Productions is best known for its quirky, intelligent, and well-written games and its willingness to take on otherwise unexplored concepts with its titles. They're the darlings of game development and their reputation has been well earned.
The studio has since put three of its PC titles on sale in a single, heavily discounted bundle on Amazon which includes Costume Quest, Stacking, and their masterpiece, Psychonauts. The bundle costs a total of $9.99 and purchasing it provides you with keys to use on Steam.
If you haven't yet had the chance to experience these games, now's good a time as any to pick them up. Do it before the sale ends.