Over the years, my collecting focus has changed a number of times. The constant through all of that, though, is about 10 postwar cards that I envision as the 'end state' of my postwar collection. As another poster said in the thread about owning a '52 Mantle, I hesitate to buy them (all) since it would essentially end my postwar collection.
That march has slowly started though, so if I had to stop at one, it'd be the only one of the ten that I currently own, a 1953 Topps Jackie Robinson.
Regards,
Richard.