Pre-War, gotta be N162 Kelly (not mine, but really wish it was!)
Goodwin Champions Kelly 97 Sloate 2008.jpg
Post-War, there are many near ties in my mind, but love the '54 Topps Williams #250, including back with the comic style history
1954 Topps Williams 5.jpg1954 Topps Williams 5 back.jpg
Honorable mention- love the '53 Mays' front/art.
1953 Topps Willie Mays.jpg