Doctor Who: The Moonbase (1967) written by Kit Pedler and directed by Morris Barry
Second Doctor Patrick Troughton tries to land the TARDIS on Mars, so naturally they show up on Earth's moon. The year is AD 2070 and the Earth's weather is run from a moon base near where the Doctor and companions land. The base has a virus or plague that is slowly incapacitating the workers (who are all scientists). Blame falls on the newcomers though the real problem turns out to be an infestation of Cybermen!
For two of the four episodes, the video has been lost. Animations were created to fill in for episodes one and three, much like for the Reign of Terror DVD. The animations don't really capture the amazing expressiveness of Troughton's face, though otherwise they match the visual style of the story well enough. The audio is the usual high-quality sound effects from the BBC. The Cybermen are a classic and enjoyable set of villains--they aren't shouty and over-the-top like others but still have plenty of menace. Seeing the female companion Polly asked to make coffee is nicely balanced with her coming up with a chemical concoction to take out the Cybermen. She's not just a pretty face who screams and passes out when the Cybermen show up (though she does do that too).
Recommended with the caveat that it's half-animated which may be a turn off for some viewers.