ThinkFun, the company formerly known as Binary Arts, has been a mainstay in our Games 100 lists for years. The company's name may have changed, but its ability to charm and amuse has not. ThinkFun specializes in handheld puzzles that give your brain a charge with nary a single battery.

You lay a puzzle card on a grid of holes, placing the pegs (tree stumps) and planks (logs that connect pegs orthogonally at several different distances) where indicated. The hiker starts on a stump on one side of the card and must travel to a stump on the other side by moving logs, which he uses as a path from stump to stump. Your hiker can only pick up, or put down, a log adjacent to his stump. The 40 puzzles range from easy (as falling off a log) to some real stumpers.