The BFI film archive is a huge collection of some of the most interesting film and television ever made, with some of films dating back more than 100 years. Most of the archive is British, but does feature some 'internationally significant holdings from around the world'.
The website claims that the collection includes 'A wealth of material of every genre from silent newsreels to CinemaScope epics, from home movies to avant-garde experiments, from classic documentaries to vintage television, from advertisements to 3-D films, soap opera to football'. What is really interesting is that they have recently released a large amount of their films onto Youtube, and every single video I have watched has been very charming. Below, for example, is a film from 1970 entitled 'Rush Hour'. It is by the British Transport Commission's film section, which was set up in 1949 for the purposes of training and external promotion.
I find the ongoing theme of the clock ticking makes it very engaging to watch, and shows how little needs to be done to make a film really successul in its purpose.