7. Jackson Lake
When David Morrisey appeared as The Doctor in 'The Next Doctor', the first question on everyone's lips was 'Is this the Eleventh Doctor?' Personally I'm glad he wasn't...Matt Smith is my favourite Doctor by a mile, but there's no denying that Morrisey was brilliant too. And an episode that introduced the next Doctor a few stories before the previous Doctor's regeneration would be pure brilliance. It's something I hope we get to see. With all the furore over who the Twelfth Doctor was going to be...and the inevitability that you can't keep a regeneration a secret in today's internet-spoiler-obsessed age - how brilliant would it have been to have Peter Capaldi's Doctor turn up in the latter half of series seven/33? Though, being fair, at least Moffat was able to use that trick with the next companion. Of course, as we all know, Jackson Lake wasn't the Doctor after all. He was a 19th Century maths teacher whose brain was taken over a Cyberman infostamp and made to believe he was a newly-regenerated Doctor. With a new companion 'Rosita', and his own Tardis (Tethered Aerial Release Developed In Style...or more simply a hot air balloon) he was ready to take down the Cybermen menace. Only an encounter with the 'real' Tenth Doctor, revealed who he really was, and in the end, with his son Frederick returned and Rosita Frederick's nanny, he looked set to return to his old life...though armed with a little more awareness of the dangers in the world. There's still a lot of potential with Jackson Lake as a character. Perhaps he decides to continue the good fight, ridding England of alien menaces even before Queen Victoria established the Torchwood Institute. Thirty years later we see Vastra, Strax and Jenny working with the Doctor. They're not on this list simply because Moffat has already stated his intention for this brilliant trio to return. How about teaming up with an older, more experienced Jackson Lake? Or if you don't want him in the latter years of his life, how about another thrilling adventure a few year's on from his experience with the Cybermen...calling on the Doctor to help him when all seems lost? David Morrisey's recent role as the Governor in The Walking Dead helped bring a greater lease of life to that show. How about an encore performance in Doctor Who?