Eureka 7 is a debatable one. I personally disagree as I thought the first is excellent but a few people prefer the 2nd.
Fate/Zero easily.
Soul Eater
I agree with this one.
Fate Zero's second OP is definitely better.
Macross Frontier comes to mind. Triangular has grown on me since I finished the series, but I never skipped Lion, ever. Definitely debatable, though (but of course, everything's up to taste).
Psycho-Pass as well.
Lion is pretty damned good too.
All I remember about R2's OPs was "I COBTIBUE TO FIIIIIIIIBE"
Blood-C 2
Oh my God.
It's anime Twilight.
Ohhhhh man. Just you wait. This show is legendary.
Saya is so moe.
It's weird how they only make one song and yet sometimes that song is still worse than at other times.
The one time I liked it was Coppelia's casket, the Noir opening.
I as expecting the Sailor Stars OP. I hardly even process the first OP as changing - changes in the animation, even if several times, just don't make as much of an impact as changing the song after a hundred and sixty episodes.
Definitely my favorite of the Sailor Moon openings.