I usually put OP and ED together since it is the blend of music with the visuals that I rate first when I nominate a ED and OP. I did it with
Ohisama because the cheerful and tongue-in-cheek tone of the song goes very well with the rather surreal school play.
Feel so Moon also comes in mind. Oldest example I have in mind for what I mean about blend of visuals and music would be
Drivers High, the GTO OP. For 2013, expect me to nominate So no Chi no Sadame, the first OP of JoJo's Bizarre Adventures, and Out of Control, the second OP of Psycho Pass.