I enjoy the simplicity of this one. Some ambiguous black structures. There's a special bonus in this one; it's a book cover for Pandora by Peter F. Hamilton. If you haven't read any of his books… give him a try.
I enjoy the outpost-like feel of this one.
Most of this list is things manufactured on or in an asteroid. This one has a nice unique flavor; as it's more like a space creature that either naturally appears as an asteroid, or something took over the asteroid.
I was quite intrigued by the ring design of this. It's definitely a creative way of capturing an asteroid, giving lots of control over how it's processed and moved around.