He's definitely one-of-a-kind.
→ 정말 특이한 친구야.

[예문]

A: Interesting meeting your friend bob last night. He's "unusual".
A: 어제 밤에 네 친구 Bob을 우연히 만났어. 겐 정말 독특해.

B: That's putting it mildly. He's always well-intended, though.
B: 좋게 말하면 그렇지. 의도는 언제나 좋아.

A: I got that about him, yes. His laugh really cracked me up!
A: 나도 그건 알겠어. 근데 웃는 거 보고 진짜 '헉'했어.

B: He gets that a lot. He's definitely one-of-a-kind.
B: 자주 그래. 정말 특이한 친구야.