1) the settings were very convincing - the Dalek city (OK, we know with the eye of hindsight that it was a model shot), the sense that this was a big landscape with forest, swamp and caves.
2) Barbara's romance with Ganatus - there is surely some fanfic dealing with that somewhere?
3) The devious Doctor, sabotaging the TARDIS deliberately to get a chance to explore the city.
4) The time travellers, despite Barbara's relations with Ganatus, are all set to just bugger off and leave the Thals to their doom at the end of episode 4.
5) The end of episode 6 is indeed a literal cliff-hanger - with a brutal resolution
6) Terry Nation's attack on pacifism. A lot more ideological than I remembered from the book.
7) The Daleks at the end talking about the total extermination of the Thals practically raise their plungers in Nazi salutes - sounds silly when I describe it but actually very effective.
8) the one bit that really didn't work - the fight at the end; the time-travellers and Thals win too easily.
Anyhow, well worth it. I watched with the closed caption commentary, which to be honest was more annoying than helpful on the whole. Though it was interesting that the very day of the filming of the Doctor's first encounter with the Daleks was 22 November 1963, the day before the first Doctor Who (recorded over a month before) was to be broadcast, and also the day of John F Kennedy's assassination. (And of the deaths of C.S. Lewis and Aldous Huxley; but who remembers that?)