The ferris wheel scene from Junjou Romantica. The whole series is really romantic, but I think this is the most romantic part because it's the first time Misaki really admits his feelings to Usagi-san.
All from アニメ エンジェル Beats! ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ Yui: But I can't move! My body can't move! Will あなた still marry me?
Hinata: I'll marry you! No matter what kind of sickness あなた have! Even if あなた can't walk または stand, または even when あなた can't have kids! I'll still marry you! No matter where または how I meet you, I'll fall in 愛 with you. If I can meet あなた again, against the 6 billion to 1 odds, and even if your body can't move, I'll marry you.
Yui: Thank you. ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ Kanade: I noticed when I stabbed あなた the first time, that you, that あなた didn't have a heart. あなた regained all of your memories when あなた fell asleep on 上, ページのトップへ of my chest. あなた were listening to the rhythm of your own heartbeat. Yuzuru, please. tell me, repeat what あなた just said. Otonashi: No, I won't. Kanade, you'll disappear!
Kanade: Oh Yuzuru, please.
Otonashi: I can't. I CAN'T DO IT.
Kanade: Yuzuru! Please let me believe in everything あなた believed in. Let me believe that, life is worth living. Yuzuru.
Otonashi: Kanade, I 愛 you. Let's stay together forever. Let's stay together forever and ever ok?
Kanade: Ok, thank you. Thank あなた so much. Thank あなた for loving me.