根据搜索结果，韩剧《仅此一次的爱情》（Oh My Angel）中包含以下经典台词：

核心告白台词

- "You are my angel. Oh you are my angel. Always you're here. Oh you are my angel. You are by my side. Always always stay here forever."

（你是我的天使。永远都在我身边。永远永远在一起。）

情感表达金句

- "I give my confession to the wind, my admiration to the rain, my passion to the sun, my tenderness to the moon, leaving only a shattered heart in the wind."

（我把情话给了风，把爱慕给了雨，把热情给了太阳，把温柔给了月亮，独留一颗玻璃心在风中凌乱。）

角色心声经典

- "You are my first love. I hope to confess my feelings to you on a day when the weather is just right..."

（你是我的初恋。我希望在天气刚刚好的日子向你告白……）

矛盾情感对比

- "Why use sincerity to get hurt, ending up with cold heart？ Why use importance to get ignored, ending up with indifference？"

（何必用真心换来伤心，最后只剩寒心？何苦用重视收回漠视，最终只有无视？）

以上台词均出自该剧，涵盖告白、情感矛盾与角色心声等核心主题，可体现该剧对爱情细腻的刻画。