Honus Wagner played for the Pittsburgh Pirates from 1897 to 1917. His Baseball card is worth a whopping 2.8 million. The reason it is so expensive is because there were only 200 every made and the reason that there were only 200 ever made was because the tobacco company was making them and Honus was not for the smoking.
Jackie Robinson's baseball card is the first colored baseball card ever made. It is worth around 10 to 15k
Babe Ruth Is very famous for his "called shot" in the 1932 world series against the Chicago Cubs. His card is also worth a lot of money at just over 515,000