Terminator 2: Judgment Day (1991)

James Cameron's Terminator 2 was the first film in history to cost over $100 million to produce, pioneering liquid metal CGI effects that earned it 4 Academy Awards including Best Visual Effects. Arnold Schwarzenegger returns as a heroic T-800 sent to protect a young John Connor from the liquid-metal T-1000 (Robert Patrick), reversing the original film's dynamic. The film grossed $519 million worldwide and remained the highest-grossing R-rated film of all time for 20 years.