Cylon by Michael Lark.

This is the classic Cylon design from the series that aired back in 1978 in a show called Battlestar Galactica. A favourite show of mine at the time, as it was set in a universe where man had created robots only to have them turn on their creator and almost wipe him out.
The more recent re-imagining of the show was actually a great improvement, although it let me down a bit in the end as it moved from hard science fiction into fantasy (by my definition) but I enjoyed the journey.
I came across Michael Lark's work in a comic called Terminal City which had some great robot design's littering an excellent tale by Dean Motter. His work is very gritty and fits the tales he illustrates particularly well, for me the peak being his run on Gotham Central which follows the police trying to stamp some kind of authority in Batman's Gotham City. But that said his run on Captain America was also great.
Michael visited the UK in 2006 and attended the Birmingham Comic Convention (BICCs), which sadly no longer takes place. I mentioned his commissioned Cylon image (which he did for me in 2005 through web contact) as he did a great convention sketch for me of one of the main robots from Terminal City (I'll post it up sometime soon), hopefully it made a nice change from Batman and Captain America.