2. 'The Terminator' (1984)
The premise is so brilliant you can't believe it was hiding in plain sight; that no one before Cameron latched on to it. A veteran of a post-apocalyptic future war must travel back in time to save a woman from being killed by a murder-programmed cyborg. That woman has yet to birth the leader of the future's resistance force, but she will, and Skynet's machines must stop it.
In terms of plotting and structure, Cameron's script is a Swiss watch -- it's breathlessly paced and effortlessly entertaining, minus the dated 80s production values. "T2" is almost a bigger-budgeted (but less tight) redo of this film -- they share virtually the same climatic car chase that takes them to an industrial warehouse showdown. Of the many (mostly unwanted) installments in this franchise, the best of the bunch is still the one that started it all.