one in a million 万里挑一;百里挑一

【例句】
That mind of yours it's one in a million.
你这头脑真是万里挑一的好。

This year's Footballer of the Year is one in a million – few other players can compare.
本年度的“最佳足球运动员”真是百里挑一的球星！其他球员无法与之匹敌。