WaLE drone by Yappen All Day Long. It's full of weird angles and protuberances.
Random Mech Thingy by ISwiperGoSnipin. This one looks to have a few Brickarms parts included in the build.
The Q-R270 by The Extra Brick. I found this in the Micro Military group. The photograph is a little dark though.
This one by Justin Pern is brilliant! I may have to build a copy. Unfortunately he doesn't allow downloads. So your going to have to trust me and click on through.