The ONE movie you would recommend.

I put the question out there on twitter and got a great response. If someone had never seen a movie before, and you could only recommend them ONE film to watch, what would it be?

Your reason for picking a film doesn't matter, or if it's considered a 'great', as long as you love it!

Here's all the movies people picked. I was adding any from the comments, but I'm now going to stop adding to them as there's too many!