Unlike Max Max, this film's success cannot be measured by a slew of imitators, and unlike Night of the Living Dead, there's not much you can do to improve on it either. The concept of time travel wasn't new to cinema: putting it in a non-stop SF-action context, however, was a startling twist, and the execution is so solid, its domain has largely been left alone by other movies, save the sequels. Human soldier Biehn is sent back to save the mother (Hamilton) of John Connor, who will eventually become leader of the resistance against the machines; Arnold is perfectly cast as the unstoppable cyborg assassin who wants to prevent John from existing.
As with all time-travel movies, if you think about the paradoxes, your head will explode, and only once are the two main protagonists in the same frame, but Cameron rarely gives you the chance to breathe - there's effectively no dialogue between the leading characters for the first 40 minutes. The effects hold up well, not least the Terminator's transformation into a metal skeleton - though by the final stages, Sarah is reducing to crawling away backwards, to get round the pesky truth that she could simply amble to safety. No matter. This is a great, simple concept, kept free from unnecessary complications, and fully deserving a place in the action film hall of fame.