I love collecting vintage baseball cards, as well as modern and ultra-modern cards! But sometimes, you get in danger of trying to collect everything! So I decided to invent "The Dandy Dozen," which is a list of 12 cards from each era, in each sport, that I'm going to target for my collection. It doesn't mean you have to buy the rookie cards of these players, but by buying any of their cards, their values should continue to rise, and you can work toward improving either the year of the player's card, or the grade of the cards.  Let me know in the comments which players I left off -- and who on this list you would replace them with!