This Game is indeed an awesome opening! Would definitely be part of my Top 10 Anime Openings if I would make such a list :)

I always find it hard to decide on the number one but I guess concerning Endings it would be “scaPEGoat” (1st ED of Owari no Seraph) for me. There are so much more I love as well, though! And I guess my decision would also depend a little bit on whether I would just judge the song itself or also the video/the cutting or the impression the ED makes. The ending of “Angels of Death”, for instance, isn’t a super special song in my opinion but it’s damn awesome when it starts in the show!