Well, not for nothing, but Mr. Shatner is classically trained as well in Shakespeare.
Not to take anything away from Christopher Plummer, because his performance was spectacular, but it's unfair to say that his portrayal of Chang was the best Klingon performance. To do so implies that Klingons are one dimensional characters and are all exactly the same. You can't say that anymore than you can say that Shatner plays the best human (or even Captain for that matter but that's another debate).
Klingon characters in Trek have always been very diverse. Just look at the original three Kang, Koloth and Kor and how completely different each one of them was and how rich they were as characters. One of my favorite characters of all time is Martok and not because he's a Klingon but because he was such a brilliantly written and developed character and nobody could have played him like J.G. Hertzler. The same goes for Michael Dorn as Worf, Andrew Robinson as Garak, David Warner as Gul Madred (and Gorkon, too), Brent Spiner as Data, Leonard Nimoy as Spock and of course, Christopher Plummer as Chang (obviously, that's an abrbreviated list).
Star Trek has been very blessed over the years to have excellent casting directors who have sought actors who have their roots in the theater as well experienced Hollywood character ators. In my opinion, these "working actors" were always better choices because they were professionals who studied their character and felt it was there job to make those characters come to life and become believable.
So to correct the premise, Christopher Plummer played Chang better than anyone could have.
-Shawn
