The phrase "undisputed king" means someone who is widely recognized and accepted as the most superior or dominant in a particular field or area. Full definition
Pros: A crusher in a tux, and still undisputed king of 911s. (autoweek.com)
If you are worried that the move will have left some early adopters out in the cold, don't be - the Prime HD never made it to market as far as we know, so that means the Infinity is the new undisputed king of the crop from Asus in the tablet stakes. (pocket-lint.com)
Director Todd Phillips is the current undisputed king of frat comedies, even though the only movie he has directed that truly falls into that category is Old School (but do you really need any others?). (filmjunk.com)