Interesting this thread came up...  just yesterday, my wife made me go through my old cards and do something with them.  Well, my wife is donating 98% of them to some place...  I do have a few that I need to look more deeply into.  Several 50's and early 60's cards like Mickey Mantel, etc...  none of the cards that have sold for stupid money in the past..
I do have a Walter Payton rookie card as well as an interesting card...  when Magic Johnson's son was born, he had one of the major card makers make a run of about 30 cards with him, his wife, and the baby boy (the kid that's a fashion/media person today).  The actual printer ran an extra sheet of the cards and gave me one.  So, I got one of the 6, 10, or whatever the number was (not many).
I always wanted a David Thompson card; however, his rookie year, the cards, I believe, were an oversized card and his was expensive at the time...  never bought one...