My favorites are number 4 by tsbranch, number 7 by Daniel Murray and number 12 by Noah Whyler. Though 4 does make me think of a more distinguished Raven, the design is very well done. Number 7 amazes me, it's so close to looking like an Alex Ross painting. If the costume was a well done as the face, would have just assumed it was Alex Ross' work.
Number 12 just for style reasons alone. Body proportions are all obviously 'wrong' in the natural speaking sense, but it kept to the theme that's been created. I think it won over all stylistically speaking, for me at least. Something, maybe not completely new, but still fresh and interesting enough to stand out from the rest purely through style.
Personally speaking though, out of the 3 would really like to see a Thor comic done in number 4's style the most. But that's just from my own design taste.
Side note, glad that some of these other ones refrained from sticking Mjölnir between her butt cheeks or cleavage, since that's all they seemed to be interested in drawing.
