Trigun OP (H.T.) vs. Ranma 1/2 OP1
I wish Trigun mixed it up a bit more - the music is a wee bit repetitive, as are Vash's badass poses, but it's solid. Ranma's is also catchy but the art style is weirdly worse than the show, and too much dancing Akane + zoom in on her short shorts. Buh.
Speed Racer OP vs. Eureka Seven OP4 (Sakura)
Slaughter. Eureka 7's opening was shockingly badass. If only the singer was better, the backup instruments are great, as are the opening visuals.
Rune Soldie Louie OP (Twinkle Trick) vs. Great Mazinger OP
Nothing special about Louie and very dated. Mazinger at least has exploding insets.
Key the Metal Idol OP (In the Night) vs. Eden of the East OP (Falling Down)
I like Key's opening a good deal, though it's a wee bit slow to get started. Still, easy vote.
GaoGaiGar Grand Glorious Gathering OP (Yuusha-oh Tanjou! -Grand Glorious Gathering Version-) vs. Bleach OP13 (Melody of the Wild Dance)
More meh giant robots. Unexpeted OP for Bleach, though, doesn't seem to fit with the tone of the show.
Naruto OP2 (Haruka Kanata) vs. Tsukihime OP (The Sacred Moon)
Wow. That singer for Naruto... sucks. Not great visuals either. Another slaughter.
Yumekui Merry OP (Daydream Syndrome) vs. Macross II OP (The Hush of 200 Million Years)
Macross's opening is okay (although the clothes disintegrating as that one girl runs is strange). Yumekui Merry's is just really neat though, even if the fashion sense of these ladies is nonexistent and fanservicey.
Sayonara Zetsubou Sensei OP (Hito toshite Jiku ga Bureteiru) vs. Yu Yu Hakusho English OP1
They're both good but not great (although SZS's is a bit creepy).
Endings
Tenchi Muyo English ED1 (Talent for Love) vs. Chobits ED2 (Ningyo Hime)
Tenchi Muyo's is pretty darn good.
Azumanga Daioh ED (Raspberry Heaven) vs. Basquash ED 2 (Futari no Yokusoku)
Fear the basketball robot and its backup singers? Easy vote anyway, I'll take active.
Gankutsuou ED (You Wont See Me Coming) vs. Freezing ED (Kimi wo Mamoritai)
Fun + good visuals vs. Ken Burns effect on softcore anime porn. Uh huh.
Turn A Gundam ED (Tsuki no Mayu) vs. .hack//SIGN ED (Yasashii Yoake)
Yasashii Yoake is one of my personal favorite songs ever, so tough match for Turn A. I think the short-version of Yasashii Yoake still works great, while Tsuki no Mayu needs the long 4 minute version to be at its best anyway. And .hack//SIGN wins on visuals anyway, too.