There's a lot to really choose from, but at the top of my head, and in no order;

"Eyes on Me" on the Ragnarok.
Orphanage Flashback (mostly because, I liked how they foreshadowed it).
Edea's Parade.
Garden Battle (though the Rinoa scene was flawed).
Garden Takeover.
Squall and Rinoa in FH concert.

I'll add more when I think of them.