50's - 51 Bowman Mantle as I'd rather have a "true" rookie card
60's - 68 Topps Nolan Ryan RC, he was my favorite player as a kid
*now this may break the rules, I dunno...the original post didn't say it had to be all baseball even though this is in the baseball section
70's - 76 Topps Walter Payton RC
80's - 86-87 Fleer Michael Jordan RC
90's - 92 Upper Deck Heroes Autographs Ted Williams