Plot: the Time Lords send the Doctor back in time to Skaro to stop the Daleks being created, fearing they will come to dominate the universe.

Ironic if Tom Baker didn't like the Daleks that he acted in this, for me the best Dalek story in fact the best Dr Who story. A story which takes itself seriously from the Doctor agonising over whether it's right to destroy the Daleks, to the chilling moment as the Daleks turn on their creator Davros. The warped scientist Davros was so memorable that he was resurrected for another four stories.