RobotMan by Duncan Fegredo.

Robot Man is Clifford "Cliff" Steele a human mind in a robot body, and DC hero who is part of the strange superhero team that is Doom Patrol.He has appeared in all versions of the Doom Patrol comics, although his powers have varied a little along the way, and I'm not sure if his human brain wasn't replaced by a CPU at one point.
A great design though and a great character who had to constantly fight the depression that was caused by him living in a metal body.
Duncan Fegredo is one of the nicest comicbook artists on the Con circuit. He always seems to be enjoying himself, regardless of the daunting queue at his table, and his talent has recently landed him the job of bringing Hellboy to the comic page, which is the highest praise.
I got this quick convention sketch back in 2000.

CLANK !!

The Coffin by Mike Huddleston.

Phil Hester and Mike Huddleston produced a really interesting mini-series a while back called The Coffin.
Dr. Ashar Ahmad a brilliant but heartless scientist was intent on proving the physical existence of the soul, going as far as to create an impenetrable cybernetic skin that would trap the human soul after the body within has died - a walking coffin. As you might expect, a dying Ahmad ends up encased in one of his prototypes and then realizes how he'd wasted his life. Things go from bad to worse as The Coffin begins a desperate race to reclaim his technology from an evil corporate overlord and and the same time save the life of his estranged daughter.
I enjoyed the book and loved the design of The Coffin (who I guess you could argue isn't really a robot).
I was lucky enough to get out to the San Diego Comic Convention back in 2001 and got this convention commission sketch from Mike himself.