Star Trek III has one of my favorite villain/hero stories in the entire series, even more so than the Wrath of Khan*.
I just liked how in The Search for Spock, there are three stories going on. One with Kirk and crew, one with David and Saavik, and the other with Kruge. The Kruge dynamic is great because this is a villain who knows nothing of Kirk short of being involved with the Genesis Device, and is only going after the Genesis Device for his own personal gain and not for some typical revenge plot. And when Kirk and Kruge finally meet, nothing is the same. Of all the times Kirk has used his diplomacy and authority to get what he wants out of his foes, it's Kruge that pins Kirk down.
And not many fans say this, but I find the destruction of the Enterprise to be a perfect example of Kirk finally accepting what the "No Win" scenario was all about. No matter how good you are, no matter what choices you have, you will always lose something as a result. He never saw it that way because he thought he could save everything like his ship and the Maru, but it wasn't until TWOK where he literally faced the no-win scenario for real. Not in the sense that klingons come in and blow up the Enterprise, but that no choice you made would lead to a good one (leave the maru to die, or try to rescue the maru and die yourself).
*I AM NOT DISSING TWOK! I LOVE TWOK!