Since its premiere in 1963, Doctor Who has been telling tales of a time traveling shape shifting alien known as The Doctor. Hailing from the lost planet of Gallifrey, The Doctor is a benevolent alien who seeks to promote peace within the universe, and oftentimes, on Earth. Along the way, he - or she - acquires companions to join him or her on the journeys they take throughout the universe.

Doctor Who may bill itself as a time traveling, science fiction based adventure series, but at the heart of every good adventure, you’ll almost always find a love story. Whether it involves one of The Doctor’s many companions falling in love with him, or the companions falling in love with each other, love stories are as integral to the DNA of Doctor Who as space itself - especially since the relaunch of the series in 2005.

That’s not to say that every romance is created equal, however. In fact, there have been plenty of bad ones. Here, we take a look at the best and worst of the bunch.

Best: Vastra and Jenny

Representation matters in all its forms. In the case of Doctor Who, one of its most forward thinking examples of representation came in the form of the inter species relationship between female alien Vastra and human Jenny. The duo have always been presented as deeply in love, committed to one another, and brilliant investigators.

Doctor Who never lets their Victorian time period, or their unique inter species status, serve as any sort of barrier to their relationship and its openness and acceptance. Homophobia has no place in the world of Doctor Who - and neither apparently, does inter-species-phobia.

Worst: Mickey and Rose

From the moment Rose Tyler and Mickey Smith are introduced in the first episode of new Who, it’s clear that these two should never have been in a relationship with one another. They seem as though they are the sort of couple that just got together because there were no other options - as if high school sweethearts who outstayed their welcome, and never knew there was the potential to look elsewhere.

It certainly doesn’t help matters either that, from the moment she meets The Doctor, Rose hardly pays poor Mickey a passing thought. It’s not entirely like she can be b.amed for it, considering the types of adventures that The Doctor takes her on. But Mickey is treated as an afterthought, almost unworthy of a decent breakup. And that’s a real shame.

Best: Amy and Rory

When Rory Williams, nerdy nurse in training, is introduced in the first episode of season five, “The Eleventh Hour,” Amy Pond, The Doctor’s new companion, seems almost embarrassed to admit that the man is her fiance. By the time the duo ended their tenure on the series midway through the seventh season, they were ready to die for one another.

As the kids say these days, that’s quite the glow up. While their relationship had plenty of ups and downs - not least of all jealousy on Rory’s part due to Amy’s misplaced attraction to The Doctor, and the dizzying saga of Amy’s pregnancy and eventual giving birth to River Song - it was clear from day one that these two crazy kids were meant for each other. They waited thousands of years to be together, after all.

Worst: Bill and Heather

As we’ve already said, representation matters, regardless of the form it comes in. So it was about damn time, really, when Doctor Who finally introduced an LGBTQ companion in season 10’s Bill Potts. It’s just a shame that the series decided that the best way to give her a love story was with the introduction of Heather - a girl she admired from afar, who became a victim of one of the series’ aliens of the week.

Heather was turned into some weird dimension defying traveling liquid alien spirit sort of thing (really, it’s not any easier to explain than that), and would appear again in Bill’s swan song episode. Further adding insult to injury, Bill decides to take the now ghostly alien Heather up on her offer of traveling with her, becoming part of her same alien species in order to do so. It’s confusing, and frankly disturbing, and not at all one of Who’s best writing moments.

Best: Martha and Mickey

We don’t get to see all that much of Martha Jones and Mickey Smith together as a couple, but the little glimpse we do receive of them toward the end of season four’s specials is enough to convince us of their status as a true power couple. Martha and Mickey were two characters who found themselves in hopelessly unrequited situations. While Mickey loved Rose, and Martha pined for The Doctor, neither of those characters ever meaningfully returned their affections.

So it’s fitting, truly, that these two characters would find their happily ever afters in one another. Not only do they finally get the love that they deserve, they also get to prove themselves to be heroes in their own right, after all the adventures they took part in alongside The Doctor years before.

Worst: The Doctor and Amy

One of the weirdest decisions the new Doctor Who has ever made was arguably the choice to have the Eleventh Doctor meet a young Amelia Pond as a child, befriend her, act fatherly toward her… and then have a twentysomething Amy Pond fall in love with him and, while engaged to another man, aggressively throws herself at him.

Doctor Who has developed a real complex when it comes to showing companions falling in love with the white knighting Doctor, but few instances of this behavior have been as downright disturbing as the relationship between Amy and The Doctor. The Doctor always acts in a paternal, protective way toward her, but Amy’s interest is romantic in him for nearly an entire season - and perhaps longer, if the way they bait and draw out unnecessary tension is anything to go by.

Best: Danny and Clara

Doctor Who isn’t something that’s usually thought of as a romantic comedy, but the relationship between fellow schoolteachers Danny Pink and Clara Oswald is pretty much as close as the series gets to being just that. The series’ eighth season shows Clara struggling to balance her life at home with her life as a time traveler, and one of the biggest struggles she has is finding a way to make space for her love for Danny.

From the very beginning, the duo are perfectly suited for one another, shyly flirting in the school’s classrooms and eventually opening up enough to be able to discuss past traumas. But just as Clara seems to have found the balance she so desperately needs, and just as she is ready to admit aloud to loving Danny, he is cruelly taken from her time and again in some of the series’ most heartbreaking scenes to date.

Worst: The Doctor and Rose

This is definitely one of the more controversial takes on this list, but we have to admit that it’s true: the relationship between The Doctor and first companion Rose Tyler was one of the biggest mistakes the series has made to date. Not only did it set the precedent for almost every companion falling head over heels for The Doctor, even when the development may never have been there, it also does damage to what could have been a stronger, more interesting character in Rose.

Rose, in the first season, is much more interesting than the moon eyed, swooning, foolish Rose in the series’ second season. The love story that Doctor Who tries to sell as existing between Tyler and Tennant’s Tenth Doctor is harder to believe in, from a writing standpoint, than any of the intricately crafted alien races the series spends so much time world building in its writing.

Best: The Doctor and Idris/The TARDIS

Companions may come and go, but at the end of the day, there is only one relationship that The Doctor can rely on: his relationship with his TARDIS. The season six episode “The Doctor’s Wife,” artfully written by science fiction and fantasy writer icon Neil Gaiman, elevates this relationship to an entirely new level, introducing the character of Idris, who embodies the very being of the TARDIS in humanoid form.

While The Doctor always talks to his TARDIS, this episode represents the very first time that viewers are able to understand just what the TARDIS says back to him - and just how strongly the two care for one another. It’s a beautiful, poignant tale that only reinforces that there can never really be a true love in The Doctor’s life, other than the one who will always be there for him, whether in the form of a human or a police call box.

Worst: The Doctor and River

Simply put, introducing the character of River Song was one of the worst choices that Doctor Who ever made. While Alex Kingston is a powerhouse performer in her own right, the character confused the overall timeline in the series more than any time traveling adventure could ever have done - and made for some terribly unhealthy storytelling.

When The Doctor meets River Song, she is about to die, with all the memories of their time together. But each time The Doctor meets River, she knows him less and less - even during the terribly confusing sixth season storyline where she knows she is meant to kill him. It’s a story that adds almost nothing to the series overall, and a romantic relationship that the series would have been far wiser to do without.