If you could only have one card...

[ls7plus]

Probably one of the following three I already own:

(1) '55 Exhibits Postcard Back Mantle;

(2) 1907 Dietsche Fielding Position Cobb;

(3) 1923 Lections Babe Ruth.

But ask me on another day, and the list of possibilities might be entirely different!
And Adam's reference to the '54 Bowman Williams makes me once more regret selling the high-end PSA 7 I sold a couple of years ago.

Best wishes in your collecting endeavors,

Larry