When it comes to Doctor Whoactors, it is hard to argue that David Tennant is the most famous and beloved to play the role of The Doctor, both in new and old Who. Tennant played the Tenth Doctor from 2005 to 2010, but even after regenerating and moving on to other projects, he returned for the 50th-anniversary special ‘The Day of the Doctor’ in 2013 and then made the unprecedented move of coming back as the Fourteenth Doctor for a series of specials in 2023. Tennant has gone on to have an incredible career, but he almost missed out on the chance of the role that made him a star if he had followed the advice of a former agent.