Terminator 2: Judgment Day (1991)

Even a machine built to kill can learn the value of a human life, and help a family fight for a future that isn't yet written. James Cameron's "Terminator 2: Judgment Day" brings back Arnold Schwarzenegger as the Terminator, this time reprogrammed and sent back in time to protect young John Connor (Edward Furlong), the rebellious boy destined to lead humanity's resistance. His adversary is the T-1000 (Robert Patrick), a nearly unstoppable shape-shifting assassin made of liquid metal that can mimic anyone it touches. His ally is John's mother, Sarah (Linda Hamilton), now a hardened warrior locked in a psychiatric hospital because no one believes her warnings of a coming nuclear apocalypse. After breaking her out, the trio set out to stop Judgment Day by targeting Miles Dyson (Joe Morton), a well-meaning engineer whose research will one day give birth to Skynet. Along the way, John orders the Terminator never to kill, and the cyborg slowly becomes something like a father figure to him, all building to a fierce showdown in a steel mill. Packed with jaw-dropping stunts and groundbreaking computer effects, it's built around a surprisingly touching human story. It won four Oscars, including Best Visual Effects.