The series arguably has multiple instances of this, however, the most powerful part has to be Hikaru's speech in the movie to Misa after the latter think's the former has chosen Mimmay over her.
Misa, after catching Minmay with Hikaru, tells him to go after her.
Misa: "Hurry and go after her."
Hikaru: "That's not it! That's not what I was thinking! When the two of us wandered across all that devastation, and barely made it back to the Macross, and heard Minmay's song in town, and saw her on the screen. That's when I knew. The one who I want by my side forever, is you. And I haven't changed my mind. I might die today, but if you can accept that about me..."