8. Cast Away (2000)
I'm violating the rules of this article slightly as to make room for Robert Zemeckis'
Cast Away, because - despite the fact that there's lots and lots of actors in the movie aside from its protagonist - most of the flick hinges on the performance of one man, and that man is Tom Hanks. Setting a film on a deserted island and having us watch a man whilst he adapts to survive isn't the most alienating concept in movie history, but it could've got old really, really fast. Nope: with Tom Hanks front and centre as stranded Fed-Ex delivery man Chuck (coupled with a truly genius plot point that gives the movie a reason to include dialogue segments by way of volleyball and best friend Wilson), Zemeckis crafts a truly entertaining picture about alienation and companionship. Hanks is a genuine revelation in the main role and does an incredibly good job of leading a movie in which he has barely anyone to act against. It would have been a mighty risk for any actor to take this role, but Hanks nails it at every turn.