Well ... I'm probably gonna sound out of place but ... oh well.
Kilika
And all for one simple reason ....
The scene with Yuna's first sending .... it was all beautifully well done, from the movements to the music included. It would have been perfect if we didn't hear Tidus's whiny thoughts after she finished. But even with the knowledge that Yuna was sending souls away ... it still gave me a sense of serenity and peace, likely from the fact that when all was said and done, she'd just helped all those souls whom were given eternal rest.
I don't know though, that may just be me like I said.