And one could add Bryce Harper to that list. While he did technically go to junior college, he did so by dropping out of high school after his sophomore year, getting his GED and then attending a JuCo, all for the sole purpose of getting drafted a year earlier, and therefore would probably be the youngest player on this list at the time of the draft.
Of course, I still wonder how many busts? Because the number of busts vs success stories determines your historical odds of success (which, on draft day, are meaningless)...