What is the best public high school in US?

There's no single "best" public high school in the US. Rankings vary widely depending on the methodology used (test scores, graduation rates, college acceptance rates, resources, etc.) and the weight given to each factor. Different rankings will produce different top schools.

Websites like US News & World Report, Niche, and Newsweek publish annual rankings, but these should be viewed as one data point among many, not definitive statements of quality. A school's "best" status is highly subjective and depends on the individual student's needs and learning style. What's best for one student might not be best for another.