The actress who is currently leading Channel Four's hit sci-fi drama Humans, Gemma Chan's career has been on the rise for a few years now, including guest appearances in these two flagship dramas. Like other future Sherlock guest star Lindsay Duncan, Chan appeared in The Waters Of Mars as Mia Bennett, one of the crew of a Martian Base who are attacked by the parasitic Flood. Unlike most of the guest actors on this list, Gemma's character makes it out of her Doctor Who episode alive. The same cannot be said for her character in Sherlock. This time Chan plays Soo Lin Yao, a pottery expert who is killed by the Black Lotus, a Chinese crime syndicate from which she had previously escaped. She should have stuck with the Doctor...
