5. Rupert Grint
Alright, I get it. Grint is ginger. The Doctor wants to be ginger before his time in the universe is up. Grint has left a legendary mark in the history of cinema and fantasy as we know it in his eight years as Ron Weasley in the Harry Potter franchise. But is that really all we're looking for? Are we really just looking to have a quick thrill when Smith regenerates into Grint and he says, "Finally ginger!" and then blindly roll the dice on his Doctor performance for the next few years? I'm not doubting Grint's ability to act by any means: Ron Weasley was one of my favourite characters in the Potter franchise and Grint was born to play him, but the console room isn't for everybody and a running gag in one franchise and a memorable performance in another on their own just isn't enough for me to stand behind this casting decision. Then again, I have high standards when it comes to my Doctor, and I know Rupert is a top choice among the fans. Who knows, maybe he can pull a rabbit out of his hat (no magic pun intended) and surprise us all with a Doctor as brilliant and more confident than our Ron Weasley.