- You think it's the best in terms of illustrating the trope.
- You think it's the most well done.
- It's your favorite play in that trope.
- You just really like the source material.
Sugar Wiki / Most Triumphant Example
This is simply what you think is the (not some of the, the) best example of any trope (an objective trope, not subjective, since this already is subjective). The "Crowning Example" if you will. There could be several reasons you think an example is the best.