I hope it's a V-neck T-shirt.

This list comes up from time to time, especially after an article goes up somewhere in the news stating a list of some sort, which invariably misses some important talent.

Eliot Porter
Clarence H White

For 21st century, I think the greatest are still mostly undiscovered so far, some of the folks on flickr, lff , here, and at workshops I've learned with have talent and images that would be easy to envy. It might have never been shared in the 20th century, and faces getting buried in the clutter in the 21st century.