I would never listen to most of the music in the OP's of most anime without the animations, but I really like the OP music with the animations in a lot of animes. Now as far as my favourite goes, hmm. I think that Death Note's music is really good throughout the show, it goes very well with what's happening and gives the show really good character (I don't know how to describe it). As far as OPs go though, my favourites are Basilisk and Speed Grapher (I really like that Duran Duran song, haha).