6. Benedict Cumberbatch
If Khan's coming back, then surely that means Benedict Cumberbatch will be too, it would be insane not to make it without him. Praise for his performance notwithstanding, no-one would be brave enough to cast yet another actor in the role. Although Cumberbatch's list of film credits seems to be growing rather rapidly, this is in addition to rather than instead of TV if his appearance in Parade's End is anything to go by, and he is currently busy filming season three of Sherlock. Looking back at his filmography, it's not unfair to assume he's the kind of actor to choose parts based on the role rather than exposure, and a Eugenics Wars TV series would give him the best of both worlds. And I'm sure someone will be able to make that shower scene relevant somewhere along the way.