My favorite one is by far the 7th one. The window would have a girl looking out of it, trees and grass would be growing everywhere the unicorn has touched, and it would be glowing in the night. I did a sketch today, that isn't included here, where it's a bit more of a perspective and you are looking a bit more under the unicorn, which I like a lot, very dynamic.
I like the 3rd one, but I think it's ripping Palencar off a bit too much. All the others I think are a touch too boring. But I would love to know what you think.