Well, Youmu, obviously. Yukari as well. I mean, being older than Gensoukyou itself should earn her some respect points =P. To add, Remilia. I just love her lines in Imperishable Night.
Also, I agree with you on the music themes. I have said it before, but man, they're good <3
Quick question: I see half of my comments trail off at the end, but there is no button (on my screen, at least) to expand them. Are you able to read the last part of them?