National Geographic is certainly a noteworthy magazine if you are looking for photography. However, LIFE magazine might be even stronger in terms of documentary photography.
As a weekly magazine from 1936-1972 and at varying intervals since then, LIFE featured some of the most widely recognized photographs ever taken on its cover and pages. From the sailor kissing the nurse in Times Square during the VJ celebrations in New York City to the image reflected in the visor of the astronaut standing on the moon, LIFE emphasized the visual impact of the events it was reporting. Covers ranged from Alfred Hitchcock and crows when his horror film "The Birds" was newly released, to Audie Murphy in uniform as one of the most decorated soldiers in World War II, to the record high number of times Elizabeth Taylor appeared, to the important events and unnoticed persons affected by wars, LIFE showed them all.