一番大事な

most important

→ 1番
phrase Rare #26,092
most important Used before a noun to mean “the most important.” 一番 means “most” or “number one,” and 大事な means “important.” It can also be followed by の when referring to “the most important thing.”
JA: 家族は私にとって一番大事な存在です。
EN: Family is the most important thing to me.

彼らの一番大事なものは

What is most important to them is

— 紅の豚 (1992)

それが一番大事な部分です

That's the most important part.

幸せになるということは世界の一番大事なです

The journey to happiness is the most important journey in the world.

彼は一番大事な問題を敬遠したように思えた

He seemed to avoid the most important issue.

一番大事な所で電話が鳴った

The phone rang at the most important part of the conversation.

それは一番大事なことです

That’s the most important thing.

私にとってあなたは一番大事な

You are the most important person to me.

— JUNO/ジュノ (2007)