Perhaps the simplest, most elegant and funnest vending machine toy, the super ball was, and is, a 2 or 3 centimeter wide ball that could be bought for a dime, and later for a quarter. While some people wasted their pocket change looking for cheap plastic cars or robots or whatever the flavor of the moment toy was, the smartest kids just built up a big collection of super balls.
Super balls are one of the bounciest things I know, and due to their small size, they could richochet off of slight irregularities in seemingly smooth surfaces. And they lost very little of their momentum from friction. So once a super ball was unleashed at high speed in a confined space, it would bounce around from place to place with no discernable course for quite a while. Of course, this high energy and unpredictable course meant that they got lost or went out into traffic quite commonly. But since they were only a dime, that was okay.
For some reason, the super ball does not seem to be quite as popular in the lobbies of our nations super markets and drugstores, perhaps because it has received too much competition from Britney Spears stickers. However, tonight I was at a nickel arcade, and in return for my roommates great pitching arm, we won some tickets that we exchanged, for, amongst other things, a super ball. They are still fun to play with, although my roommate almost got in trouble by running out into traffic trying to retrieve it.