3. A Return From Captain Jack Harkness
One of my favorite characters in the series is Captain Jack Harkness. He's great and we haven't seen him in quite some time, which is a huge disappointment because the interaction he has with The Doctor is some of the best back and forths in the entire series. He was introduced during Christopher Eccleston's Ninth Doctor run when the series was revived in 2005 and then Captain Jack made a return during David Tennant's Tenth Doctor run. He missed out on meeting the Eleventh Doctor but maybe there is some hope with the Twelfth. The character of Captain Jack Harkness comes from the mind of Steven Moffat despite being introduced during the reign of Russell T. Davis. This fact puts some hope into a return.