Wait, hold on...
I don't see Colicos as Kor on the list. Come on, he's gotta be in the running, easily!
And I'd include Michael Ansara as Kang as well.
Plus, where is Jane Wyatt as Amanda? Or the Romulan Commander from "The Enterprise Incident"? And, as mentioned, Mariette Hartley.
(And, yes, there's always Gary Seven and Roberta.)