Armando Gallaraga still has a chance I guess to be known for pitching a perfect game that wasn't.
Tom Gamboa I don't remember if he was ever a player, but he was the Royals first base coach who was attacked by the fans in Chicago during a game. He has a few cards out.
I remember Mark Whiten most for hitting 4 HR's in one game (I know others have done it too though).
Fernando Tatis is most likely remembered for hitting 2 grand slams in one inning.
Brien Taylor is remembered for being one of the best that never was. Man the hype he got.
I assume this is just baseball, you could do other sports too like Fred Dryer and Bubba Smith more famous for acting than football. The list goes on, but that's just off the top of my head.
Royal Card Review is my blog if you feel like checking it out, thanks if you do!- royalcardreview.blogspot.com/
In the process of updating my collection so don't trust any of my lists right now.