Honorable mentions:

A hive in the sky...

I like the way the clouds make the building part of the sky... well seen.

beautiful composition. and scraping at least the lower edge of the cloud layer...

Dreamy colors and an almost perfect mirror effect. Love it.
3rd place:

The monochrome really works here, amplifying the architectural geometries. Framable!
2nd place:

This was my favorite until the last minute. Super use of a fish-eye and great use of B&W.
And the winner is:

The surrealistic feel (Matrix anyone?) of this one was irresistible.