His military paintings:
http://www.history.navy.mil/ac/artis...er/draper1.htm
His portrait of JFK in the National Portrait Gallery. I wish the reproduction was larger:
http://www.npg.si.edu/exh/hall2/bigjfks.htm
Paul Mellon at the National Gallery of Art:
http://www.nga.gov/cgi-bin/pimage?62341+0+0
It's amazing that more of his work is not on the web.