Head shots of less known, but notable Klingons from Star Trek the original series:

                  

Above left to right:
KAHLESS, "The Savage Curtain"
Klingon Ship Captain, "Elan of Troyius"
KRAS, "Friday's Child"
KRELL, "A Private Little War"

These guys don't get any recognition at all; the glories go to Kang, Kor, and Koloth. One should keep in mind that THIS Kahless could cry out like Lincoln: "Four Score, and..."

Notice the Klingon logo behind that grid in picture #2. Is it SUPPOSED to be on its side? Have we been getting it wrong all these years?

[Editor's note: apparently Paramount decided it liked the upright version better, but it seems acceptable canon to use it sideways as well, based on this holo-image.]