Klingons and Humans are not from the same genetic base
Neither are humans and Vulcans. Or Bajorans and Cardassians. Unless you subscribe to the whole Precurser/Preserver story about all humanoids being descended from a single race. Now Vulcans and Romulans...
In Trek - Leeta. Couldn't stand her whining.
In STO - Leeta again, along with Slaamek (the Reman gladiator/double agent from Coliseum).