The BFI has a great programme of films that I wouldn't see anywhere else and that never make it to DVD. I've really enjoyed films from Greece, former Yugoslavia and Slovakia; I'd love to see some of them again but can't.
The frustrating thing with the BFI is that many of their films, like the Powder Keg, are shown only once or twice so it's hard to catch them on a free evening. Someone who works there told me that's all they're allowed: the film hiring contract limits the showings, the reason being that running a film is 'like scratching it with razor blades'. The material has a limited life, something I sort of knew but hadn't considered the implications of. I wish some global outfit would digitise all films and make them available. The viewing experience would be second-best but better than none at all.