The British company Spite Your Face Productions makes illustrations, animations and LEGO short-films. Their stop motion films with LEGO include Spider-Man: The Peril of Doc Ock, One: A Space Odyssey, Star Wars: The Han Solo Affair and Monty Python and The Holy Grail in Lego. The last one, that comes with the special anniversary edition DVD of Monty Python and the Holy Grail, is a remake in Lego of the 'Camelot' musical number from the film. The Daily Llama Monty Python's site says:

The deal with the Python film started when either Terry Gilliam or John Goldstone (not sure which) found this great Japanese website where the guy had made a bunch of LEGO models of scenes from Holy Grail.

You can watch the film in high resolution here or at IFILM, that also has a LEGO Films Collection with the Spite Your Face films and more. (Thanks Sizi!)