First off, let me just mention how happy I am to see you guys working on these banners

Great work, both of you! I am going to comment on what I noticed in these images, from the viewer's perspective.
To Malte:
I like how all of your banners are the same time.
Your choices of images for each of the backgrounds are very well-suited to the awards.
The transitions from the original image to the extended part of the banner, where much of the writing is, is generally very good. I realize that such a transition is difficult to achieve, and you accomplished it very well, especially in your "Friendlist Member" image.
There appears to be a little bit of a "seam" on the Philosopher and the Role Play Gamer images, but it doesn't detract from the image quality, and it probably makes the text easier to read.
To RogerRabbit:
Excellent choices of images, and good use of word art / consistant fonts.
The variation of the physical size of the images takes away some of the consistancy of the banners, and I wonder if, perhaps, the Best LBT Artwork banner is too high. I always pictured banners as long and narrow, so they took up very little space in the post. Compared to the other banners, ths LBT Artwork banner, while it looks very nice, it is significantly taller than the others. The text in all of your banners is very easy to read.
Your "Friendliest Member" image looks fantastic, and I love the use of Rooter in the Most Helpful banner.
The "LBT Philosopher" image looks very nice, though the thought bubbles detract slightly from the image. Perhaps if you wrote the words "LBT Philosopher" underneath the "Gang of five", on the left-hand side, in a similar font used on the "Friendliest member" or "Most Helpful", it may blend a little better. I don't know for sure, I'm just speculating.