Link
The acclaimed 26-episode WWII documentary "The World at War", produced by Thames Television and aired in 1973-1974, is available in full (clocking in at over 22 and a half hours).
I've always liked episode 9 - Stalingrad.
"Now it (the Sixth Army) has a new task. To fight further east than the Wermacht has ever fought before, to cut Russia in two on the Volga."
(Cue dramatic opening music)