Just before we start-- that Christina Rosetti quote was exactly what I was on about last two weeks. It's not so obscure that the audience will feel intimidated by it, but it's out of the mainstream enough that the bookish kids can feel a bit proud for recognising it, and hopefully some of the less bookish ones will go out and look it up.
This week (and probably next week and the week after) is going to be more of a work in progress than usual as the end of term/start of conference season workload catches up with me; check back as I find time to update and edit.
The End of the World: The future is into slightly misunderstood 20th-century kitsch as entertainment; use of pop song/video as atmosphere-building.
The Unquiet Dead: Alien invader that goes in for possession.
The Impossible Planet/The Satan Pit: Small crew, with a member who seems normal in some ways but is actually possessed and speaking with someone else's voice. The mechanic who dies is a trainee on their first trip.
Love and Monsters: A small group of people, initially trusting the Doctor, then turning on him because of the actions of another non-human.
Fear Her: The driver and mechanic as analogues for the nice council blokes. Alien "invader" who isn't actually invading, just doing its thing.
Gridlock: People trapped by transport media.
42: See TIP/TSP above, and add the possessed crewmember going in for repetition.
Voyage of the Damned: RTD does love his disaster movies, doesn't he?
Catchphrasewatch: "Allons-y," "Molto Bene", "No, don't do that," and another explanation that Donna's just a friend really.
Old Skool Who: "The Green Death," "Planet of the Spiders" and associated Pertwee-era stories (Doctor extolls virtues of paradise planet which turns out to contain some hostile lifeforms); "The Deadly Assassin" (companionless story). "The Horror of Fang Rock" (alien starts taking over members of small ensemble cast trapped in a perilous location, causing them to fight amongst themselves), though you could make a similar case for "The Image of the Fendahl," "Shakedown," etc. "Kinda" (possessed person who alternates between odd, animal-like movements and a kind of powerful sensual manner).
Everywhere else: Any disaster movie featuring a small group of slightly stereotypical individuals trapped in a small but imperilled environment, and/or any movie in which a mysterious entity possesses a vulnerable woman and wreaks havoc, and/or any of the recent spate of movies about emo teens whose parents don't get them (e.g. "Napoleon Dynamite"). Labyrinth ("Jared"). Poltergeist (the alien's ability to affect the electrical systems).
I've recently been reminded that David Troughton played Bob Buzzard in A Very Peculiar Practice. Skinny, championship-squash-playing, Olympic-swimming, full-head-of-hair Bob Buzzard. My word, hasn't he changed?