9. The Rowling Episode
Charles Dickens, Agatha Christie and William Shakespeare have all done it, but Russell T Davies had the idea for JK Rowling to appear in a Doctor Who episode to show kids that not all great writers are dead. It came after Rowling turned down penning an episode of Series 2 due to work conflicts, and was perhaps less exciting than first anticipated; on Christmas Eve 2008, an alien creature replaces the real world with the world of Hogwarts, leaving the Doctor (or is that Barty Crouch Jr?) to fix everything. There would've been wizards galore, and perhaps even a standoff with Voldemort. Though given that the Doctor at that point had three less lives than Tom Riddle, that could've been nervy watching. Thankfully, it was partly David Tennant himself who made sure the episode didn't happen, by voicing his obvious concerns. Why though, did no one say anything about 'Century House', a Tom McRae script about Ten appearing on 'Most Haunted' with a companion watching at home? 'Century House' was eventually replaced by Davies's 'Midnight'. Thank god.