...Why do I love like to comment on banners? D:
Baka Tenshi -- Aaaah, I really like that one with the snow effect. It's a really nice, fluid animation, from what I can see. I would do the same to my banner, if I wasn't so lazy. Anyway, the banner overall is really great. The image is positioned nicely and the background is nice and looks like a whole bunch of Christmas lights far in the distance. It makes me feel all warm and cuddly inside xD Although, I'm not much of a fan of the text. It's looking a bit odd, due to the large space in between the two lines. The font is good, though. Oh, and the blending looks a bit too blurry, but it's not too much of a bother ^^
Chikara -- That is one cute image :3 It's simple, but not too bad. The background is looking a bit plain, though, so maybe you could add some more of those glowy orbs/snow dots on, to fill up some of the space. Rendering is a bit rough around the foot, and the text stands out too much, and is kind of dull. Try using a brighter colour for the text. The font is lovely, though. And, actually, I quite like the border. The pink matches the character's hair, so there's no problem with that.
Kira -- It looks very, very... Messy. As some people have said, I don't completely know what I'm looking at. The focal point is not clearly defined, and the scan lines are a bit too strong. I sort of like the rusty colour scheme. The text stands out waaaay too much, the font doesn't match, and it distracts your view from the, er, background. Unless the text is supposed to be the focal, that is, then it should be moved elsewhere on the banner. Oh, and maybe a border would be good...
Sasuke_Darkness -- Yellow D: It's somewhat bright. Or my eyes are just pathetically too sensitive. Anyway, the flow is good on the background, and it follows the render nicely. Much like in your other banners, though, the text stands out more than the render. The stroke on the text is waaaaay too thick, and the font and text position look odd. The background is looking a bit empty, as well, and the render is too smudged. Oh, and scan lines are nice, but don't overuse them like I did. Try playing around with different effects as well.
Ryouki -- Meh, I don't mind seinen. I watch Mushishi, anyway, so...
That's an adorable render ^^ Low quality, but cute xD Considering the quality of the render, it's actually a nice banner... Is that smudging I see!? 8D -is a smudging addict- Anywhoo, the smudging and splatters are very nice. The giant blob in front of the girl (forgot her name D:) is pretty distracting, though. The text is actually pretty good, but it looks really rough, and the tiny text underneath the main text could be made smaller. And I think it looks completely fine without a border.
Gah, I rushed near the end. I shouldn't even be here posting this... -gets easily distracted-