Hikaru no Go OP - 10/10
This is one of the truly great openings in anime as far as I'm concerned. The anime itself is a classic, and this opening has become a classic alongside it. The song is J-pop at its best. The opening overall is simply fantastic. It does exactly what its job is: get you extremely fired up for the coming episode.
Final Fantasy: Unlimited ending
This is probably my favorite anime ending. FF:U was one of the first fansubbed anime I watched (and I, for one, loved it!) so this is a very nostalgic ending for me, too. But in the end it's just plain awesome and that's why I love it. Dancing chocobos for the win!