This really should be a top three, but it's got to be Androzani, so it's second or third choice that's the interesting bit. I'd be trying to pick between Logopolis, 10th Planet, War Games and Parting of the Ways, with 10th Planet probably losing out, and maybe War Games as well.
Yeah, The Caves of Androzani
was an easy top choice, but I don't know what I'd pick between The War Games
, and "The Parting of the Ways."
(I've never actually seen Planet of the Spiders