What is the oldest movie you know that doesn't feel old?

When I was a kid, I thought that old, black and white films were not worth my time because they felt dated.

Now, many years later I have seen many oldies and realised that many of then don't feel old at all. Case in point: yesterday i have seen "Rear Window" and thought how modern it feels like. And then in last minutes, when the speeded up sequence hits: yeah it's an old movie.

What guys is your take?