The Survivors

There are Daleks in this one.

Except that really, there aren't. The Daleks in 'The Survivors' are nothing like the Daleks as they're going to become; they're not vicious, merciless killers with endless ambitions to wipe out all other lifeforms and imprint their existence throughout space and time. These Daleks are the cautious, ruthlessly pragmatic survivors of an ancient war that are in the midst of vacillating between a desire to escape their self-imposed prisons and breathe free for the first time in five centuries, and a paranoid fear that their monstrous enemies have survived all this time and still represent a threat to them. These are Daleks, in short, that have not yet realized they're monsters. (Which foreshadows a later essay...)

And as such, they're strangely novel to long-time fans of the program. The Daleks will later become predictable as they change from being "the first alien race the Doctor encounters" to "the Doctor's arch-nemeses". They see something, and they either want to enslave it or exterminate it. You can actually find "Dalek flowcharts" online. But these are complicated individuals that say things like "a few questions will resolve the mystery", and actually confer about whether the prisoners are worth saving. These are Daleks that could do anything, which means that we don't know just how they'll react. It actually makes them scarier in some ways. Because they're more alien.

And if we don't know how they'll react, imagine how the TARDIS crew feels. They spend most of the episode in a state of desperate fear, from the moment that they realize that the sickness they're feeling is radiation poisoning (and oh my goodness that scene between Ian and the Doctor is just magnificent, every moment of that is so freaking amazing) to the horrified realization that Susan is their only hope, all the way through her desperate flight through the jungle. It's only six episodes into the series, but already the characters are being pushed to their breaking point in a way that the 2005 relaunch never dared. It is utterly riveting, and timelessly classic as a result.