A work regarded as an artist's or creator's finest piece—his or her masterpiece or magnum opus.
その映画は監督の最高傑作と評され、多くの賞を受けた。
That film was hailed as the director's masterpiece and received many awards.
彼女の小説の中でこれが最高傑作だと私は思う。
I think this is her magnum opus among her novels.
評論家はこのアルバムをアーティストの最高傑作と位置付けた。
Critics positioned this album as the artist's crowning work.