人生で一番

the most ... in one's life

→ 人生
phrase Rare #26,148
the most ... in one's life Used before an adjective or noun to describe something as the greatest, best, most important, or otherwise highest in a person's life. 人生 means “life,” で marks the context, and 一番 means “most.”
JA: これは人生で一番大切な思い出です。
EN: This is the most important memory of my life.

人生で一番いい時は若い時です

The best time of your life is when you’re young.

人生で一番大事なのはいい出会い

The most important thing in life is meeting the right people.

— ミッション・クレオパトラ (2002)

人生で一番いい日でありますように

May this be the best day of your life.

来るすべてに自分の人生で一番美しいとなるチャンスを与えるんだ

Give every day that comes the chance to become the most beautiful day of your life.

人生で一番よいときは我々が若いときです

The best time of our lives is when we are young.

英語で人生で一番楽しかったはいつですか

What was the most enjoyable day of your life?

— 甘い生活 (1960)

人生で一番幸せなになりそう

It feels like this is going to be the happiest night of my life.

— ウィキッド ふたりの魔女 (2024)