London (1994, dir Patrick Keiller)

Surrealist documentary written and directed by Patrick Keiller and narrated by Paul Schofield, actually shot in 1992 in London, and the first of three such films; the second being Robinson in Space Unsurprisingly early views feature an RML class AEC Routemaster, and another reflected in a telephone box:
M class MCW Metrobuses:
Another RML laying over on route 14 is revealed to be RML2343 (CUV343C) as it leaves:
A view of London General's Stockwell Garage features T class Leyland Titans and M class MCW Metrobuses:
RM901 (WLT901) arrives at a bus stop on route 36, and is followed by a second RM:
A London and Country Volvo Citybus/East Lancs pausing at the Elephant and Castle is followed by glimpses of various Titans:
A Routemaster heads down towards the camera while a sightseeing tour bus turns in the background; more clearly seen is another Routemaster passing a London Transport Leyland B20 Fleetline on open top tour duty: