The Tenth Planet has great set pieces, and a great monster. I like the Cybermen in both design and ideals; the fact that they were human at one point is creepy. Plus, these are still my favourite design of the Cybermen costumes to date. The whole thing itself is a little cheesy (why wouldn't it be? It's sci-fi from the '60s), but decent character writing makes it feel more grounded and real, and the animated reconstruction of the fourth part is very neat. It kind of sucks that the Doctor is out of commission for a quarter of it, but it's still pretty solid as a whole....