5) Rose Tyler
When Doctor Who came back in 2005, one of the best innovations that writer Russell T. Davies made to the format of the show was to promote the companion from mere sidekick to co-lead. From now on the woman at the Doctor’s side would be just as important, if not more so, than the Doctor himself. The first character who proved that this new arrangement could work was Rose Tyler (who fittingly debuted in the episode “Rose”).
Initially a bored young woman from a crowded London tower block, Rose discovered a new lease of life when travelling with the Doctor. Through her eyes, the audience got a feeling of how amazing it would be to see all of time and space and how it would totally change your outlook and make you a better person.
Rose’s slow-burning love story with the Doctor is also a favourite of many fans, culminating in the heartbreaking season 2 finale which saw the (literally) star-crossed lovers forced apart. Yes, Rose appeared a few times in later episodes, arguably lessening the impact of her exit, but her original run on the show is still a triumph.
4) Amy Pond
What marks out the best Doctor Who companions is how much they grow as people across their time in the TARDIS. In that way, the Doctor is a bit like Mary Poppins (y’all). He takes his friends on adventures until they’ve “grown up” and then he leaves them.
This is very true of Amy. Originally, she’s clearly struggling from arrested development. Over her two and a bit seasons on the show, though, Amy grows as a person – she falls in love, gets married, has a daughter and helps save the universe many, many times.
It’s not for nothing that Karen Gillan has since gone on to be a massive star, featuring as part of the ensemble cast of Marvel’s hit Guardians of the Galaxy movies. Even her Doctor, Matt Smith, hasn’t managed to appear in one of those yet.