http://www.youtube.com/watch?v=XE0K5s63xIs - Yi-Gi-Oh version of Opening and Closing, not bad.
http://www.youtube.com/watch?v=DF3vZeM8oak - Sargeant Frog version of Opening,
I came across a couple of Code Geass OPs I figured would tickle your fancy while surfing YouTube. I know the Chobits one has already been shared (and knowing my luck, the other ones will have been too), but I wanted to put them all together. Least, all the ones I could find. It doesn't help any when you can't read/speak/understand Jap. And I haven't actually seen Black Blood Brothers, so I can't vouch for the accuracy of the OP. But I did very much enjoy the Evangelion one.
http://youtube.com/watch?v=wCwN96rdEgk&feature=related – Code Geass/Black Blood Brothers OP
http://youtube.com/watch?v=BNdDbkmnBLE&feature=related# - Code Geass/Neon Genesis Evangelion OP
http://youtube.com/watch?v=wM3Byak3rko&feature=related – Code Geass/Neon Genesis Evangelion OP Comparison
http://youtube.com/watch?v=wqM2Wp9yuF0&feature=related – Code Geass/Chobits OP