2 -Terminator 2
When James Cameron created the Terminator he turned a wooden, muscle-bound ex-Mr Universe and turned him into the most relentlessly pant browning villain in cinema history. How do you top that? Well you make him the hero of course! The remarkable foresight that the one thing that would make Arnie's return in Terminator 2 interesting would be a total role reversal is the foundation of this great, great movie. Another aspect of genius is knowing that finding a bigger guy than Arnie would be A: really hard and B: look totally s**t. So instead Cameron cast the small but intense Robert Patrick and completely changed our concept of what a Terminator could be. T-1000; liquid metal. He can take on any solid object of equivalent mass, he is stronger and faster than Arnie's T-800 and is just as relentless in his quest to end John Conner. What was unexpected was the heart warming and emotional journey John and his pet Terminator take. The father son relationship they develop pushes the action to a whole new level as Arnie's Terminator protects John with the unconditional dedication of a parent. It makes you root for the Terminator and as Simon Pegg pointed out in Spaced; the death of the Terminator is genuinely sad.
Best bit: The terrifying aqueduct chase.