With Halloween right around the corner, there’s absolutely no better tip to check out Double Fine’s Costume Quest (Free). The console iteration was reviewed well, and as far as I can tell this is the cheapest the game has ever been (Unless you count paying the absolute minimum for the various indie PC bundles, I guess.).
Additionally, if you were really mad about the IAP mixup when the game launched where the iTunes description said Costume Quest’s expansion was free when it actually wasn’t, you can now buy both Costume Quest and its 99¢ expansion pack for less than the original price of the game.