i'm hoping somehow due to wacky timeyness, the next doctor ends up being john hurt. think how cool it'd be to have him for a whole series.
otherwise i reckon damien lewis would nail it, though he's probably too busy playing the worlds only ginger al-qaeda member
and for super unlikely longshot, i pick bradley walsh.
It's not entirely unlikely that Jon Hurt could be a future incarnation of The Doctor or the 12th. When The Doctor was explaining the light thingy he mentioned that it also included the days he hadn't lived yet. So it's possible that when he stepped into said light thingy to rescue Clara he saw the 12th Doctor and what he or rather would do. Also, if it were true then it would be the one possibility the fewest people are buying into.