When you see a full film or show on YouTube, all too often it's there illegally and tends to be removed fairly quickly. That's not the case with the Ken Loach content.
Loach has put up some of his finest work on YouTube officially, which includes the full version of Cathy Come Home, which I've linked to below. Once you've seen that, have a look at some of the lesser-known work too.
Cathy Come Home on YouTube