Being since I mainly collect 52 Topps cards, these are cards I'd like to own some day.
52 Topps, Warren Spahn, Bob Feller, Richie Ashburn, Joe Black, Roy Campenella, Andy Pafko, Eddie Mathews, Yogi Berra, Hoyt Wilhelm, Billy Martin, Monty Irvin, Phil Rizzuto, Joe Page, Bill Dickey and Duke Snider.
There are many others that I don't own yet either, but these are the ones I can currently think of.
Outside of the 52 Topps cards, I'd love an Aaron RC, a 56 Topps Mantle, a Koufax RC and of course a Babe Ruth card.