1.
highlight, masterpiece, most impressive part, showstopper
The most outstanding or impressive part of a performance, work, or event. Often used as a predicate: ～は圧巻だ.
Etymology
Originally from the Chinese civil service examination system — the 巻 (scroll/paper) that was placed on top (圧) as the best answer. Hence "the best part."
Usage
Most commonly used as a predicate: ～は圧巻だ (~ was the highlight). Also used as a modifier: 圧巻の～ (the stunning ~). Always positive — never used for negative impressions.