If you describe something as unsurpassed, you are emphasizing that it is better or greater than anything else of its kind.
例句
The quality of Smallbone furniture is unsurpassed.斯莫尔本恩家具品质超凡。...the Hamburg weekly, surely unsurpassed in the world for its intellectual range and quality.在汉堡出版的这份周刊视野广博，见解深刻，无疑卓绝于世