6. Rise of the Cybermen/The Age of Steel (Series 2, Episodes 5 & 6 - 2006)
In a twist of fate that only a mid-series, two episode story could deal with, The Doctor, Rose, and Mickey (yes, hes along for the ride this time) find themselves trapped in a parallel Earth. An Earth where Roses dad never died, her parents never had a child, and people wear these funny earpieces. Nothing sinister about a Bluetooth headset, right? What if it could rewrite your thoughts, control your body, and help turn you into an emotionless drone whose only service is to the hive mind? No, its not The Borgits their seasoned British grandfather, The Cybermen! Russell T. Davies once again resurrected a classic villain from the bins of time and put a modern spin on them to tell an intriguing story that introduced modern Whovians to the penalty of Maximum Deletion. After watching this episode, youll never be able to walk into an Apple Store for a Free Upgrade without wondering if something sinister is behind it. (Well, no more sinister than usual.)