A name touted for the first female Doctor, Katherine Parkinson would be just as great as a companion. In her mid-thirties, she's older than a lot of companions, but it would be interesting to see a friendship with the Doctor similar to the one he had with Donna; The IT Crowd definitely shows Parkinson in that kind of role, becoming friends with a couple of nerds despite their differences. She's got a lot of presence and a lot of experience on television, ranging from Sherlock to Doc Martin, and would thrive in such a big TV role. And how brilliant would it be if Richard Ayoade joined her and the Doctor in the TARDIS?
9. Simon Pegg
Simon Pegg actually played the villainous Editor in the first series of NewWho, but has since claimed that he doesn't actually watch the show anymore. A film star these days, Pegg is often cast as the witty, daft, human everyman, from Scotty in Star Trek, to Shaun in Shaun of the Dead. Reportedly a massive sci-fi nerd too, it would be fantastic to see a companion genuinely excited by aliens and distant planets, especially if he's read up on them, like Rory did before entering the TARDIS. It's perhaps too obvious to suggest Nick Frost as well, but either of them would no doubt have a fantastically funny and tempestuous relationship with Capaldi's Doctor.
