Tharok, a 1967 villain from the Legion Of Super Heroes.
Metallo, a Superman villain with a Kryptonite-powered heart and a metal body, circa 1959
A detailed schematic of Cliff Steele, aka Robotman, from the Doom Patrol.
Demon With A Glass Hand, the Harlan Ellison-scripted Outer Limits episode that served as inspiration for The Terminator.
A 1967 Cyberman, a year after their earlier (and clunkier) introduction in "The Tenth Planet."
MODOK, the Mental Organism Designed Only For Killing, from Marvel Comics.
Iron Man's original look, from Tales Of Suspense.
The Tin Woodman from Wizard Of Oz — don't forget, in the original 1900 story, the Woodman accidentally chopped off all his own limbs and replaced them with metal parts. Creepy!