最さいたる物もの

expression, noun

the most extreme; the epitome; the prime example

Used to single out the most representative or extreme instance of a category. Often appears in the pattern ～の最たるもの or ～の最たる例.

• 彼かれの行こう動どうは無む責せき任にんの最さいたるものだ。

  His behavior is the epitome of irresponsibility.

• この作さく品ひんは彼かれの才さい能のうの最さいたるものと言いえる。

  This work can be called the prime example of his talent.