1. STAR WARS (1977)
Motion-control photography, in which a computer is used to control a long, complex series of camera movements, made possible the spaceship battles in Star Wars. It would have taken too long to film the scenes manually, says Anne Thompson, deputy film editor at The Hollywood Reporter.
2. TRON (1982)
It wasn't the first film to use computer-generated (CG) graphics (and many effects were hand-drawn) but the sci-fi video-game fantasy flick Tron was the first to use computer imagery to create a 3D world, making it one of the pioneering CGI films. "Effects people said, 'Let's see what the computer can do,'" says Harry Knowles, movie critic at Ain't It Cool News.
3. TERMINATOR 2: JUDGMENT DAY (1991)
"Morphing" was first used in Willow (1988), but in T2 the effect was "jaw-dropping," Knowles
says. The liquid-metal robot's humanoid texture, which was layered onto a CG model, looked frighteningly real.
The rest of the list at popularmechanics.com