2. Matthew Horne Is... The Eleventh Doctor! (2009)
Neil Gaiman recently revealed that another, unnamed actor declined the TARDIS key who, if they had accepted would have become the first black actor in the role, possibly before Matt Smith was offered the part by Steven Moffat. However, Matthew Horne implied in interviews that he too had auditioned for the Eleventh Doctor, and joked that the production team had rung up the wrong Matt when it was time to pick the new Timelord. Moffat also later revealed that he had struggled to form a short-list of older actors when looking for Tennant's successor, ending up with a lot of performers in their 20s, so perhaps there's some truth in Horne's claims...