The Bowling Green Puzzle
Normally I'm not too interested in dexterity puzzles, but this one is really fun. The idea is to roll a ball of mercury down the center aisle without falling in the gutter on either side. When it hits the 10-pin holes, it should break up into smaller balls of mercury that fill as many of the holes as possible. My best is seven holes filled. Since mercury is highly toxic, I'm sure this puzzle wouldn't be allowed to be made today!