Canada's National Film Board has recently added a lot of on-line content to it's web site, allowing free access to many of it's excellent produtions, old and new. I can't get the videos to play from work, but many are available on youtube - at lower quality, but still worth watching.

In the 50s and 60s we used to get 16mm NFB films at our elementary and high schools, for showing on special occasions (or when the teacher didn't get around to planning a lesson for that day!) They also sometimes showed up as shorts before the feature film in theaters.

I don't know if many of them made it to the US, art and culture tended to flow south to north more easily than north to south.

Some of my favorites:

The Cat Came Back - goofy but hilarious, the love/hate relation ship between people and cats.

Log Driver's Waltz - catch song and cute story.

And my all time favourite, from 1971 - if you watch anything, you MUST watch this one!

Evolution - the whole story, from the origin of life, to species explosion, survival of the fittest. It even explains a huge mystery at the end, and gives a glimpse of our future - or lack thereof. You will laugh, and think, and maybe even cry.