Doctor Who is one of the longest-running science fiction shows of all time, possessing a very expansive history with a whole array of characters that have appeared over the years. Over time, the Doctor has even fallen in love. Entering the show with a granddaughter, Susan, fans have waited for decades to see the Doctor fall in love again; until he met River Song (Alex Kingston).
River Song has appeared in eleven main series stories, spanning across the Tenth Doctor (David Tennant), Eleventh Doctor (Matt Smith), and Twelfth Doctor (Peter Capaldi). A Steven Moffat creation, she mainly appeared during his era, but could always return again in the future. While only in a recurring role, to some fans she's considered one of Doctor Who's best companions.
10 The Name of the Doctor: Neglected From The Plot
River Song first appears in The Name of the Doctor during a psychic meeting between Clara, Madame Vastra, Jenny, and herself. She initially warns Clara about the dangers of the Doctor going to Trenzalore, and is present on the planet when the Doctor and Clara arrive there. The Name of the Doctor is a great story, rivalling some of the best sci-fi movies for its sciece heavy plot.
Unfortunately, River only appears there in spirit, not in her physical form. While there is a sweet moment where the Doctor notices her and they share a touching scene, some fans felt a bit let down by the half-in, half-out appearance.
9 The Wedding Of River Song: Love Breaks Time
The Wedding of River Song sees time falling apart literally because of River and the Doctor's (Matt Smith) relationship. She refuses to help fix time until the Doctor marries her, in what has got to be one of the most dysfunctional relationship moments in history.
While there are strong moments, this appearance features a much more muted River Song than in her other appearances. It was enjoyable to see her against the Silence, which are undoubtedly some of the scariest Doctor Who monsters.
8 A Good Man Goes To War: River's Identity Revealed
While River Song doesn't appear in much of A Good Man Goes to War, it turns out to be one of the most important appearances she's ever had. At the end of the episode, she arrives on Demon's Run, revealing to the Doctor (Matt Smith), Amy, and Rory that she is Melody Pond, the missing baby.
With the Headless Monks and the Faith Militant to contend with, River's inclusion would have been a welcome help to the Doctor and his party. Considering that the episode was largely about her, having her appear in proper would have been much better.
7 The Time Of Angels/ Flesh And Stone: River VS The Angels
River's first appearance in the Matt Smith/ Steven Moffat era, this two-parter features River pulling off a heist against a wealthy mob boss character, then assisting the Doctor, Amy, and the Faith Militant in taking on the Weeping Angels.
River is given a lot to do and treated almost as equal to the Doctor in terms of competence. In the TARDIS console room, she even coaches the Doctor on how to fly the TARDIS; revealing that the wheezing, groaning noise is because of him leaving the brakes on.
6 Silence In The Library/ Forest Of The Dead: River's First And Last Meeting
River Song makes her first appearance in this two-parter. Set during the David Tennant/ Russell T Davies era, River appears at the Library in the distant future, helping the Doctor (David Tennant) and Donna Noble to defeat the Vashta Nerada. Over the course of the episodes it is shown that River knows the Doctor extremely intimately, even knowing his name.
Due to the Doctor and River constantly meeting each other out-of-sync from each other's respective timelines, this marks the first time the Doctor has met River, but the last time she meets him. The episode ends with her saving the day, sacrificing her life to stop the Vashta Nerada.
5 The Pandorica Opens/ The Big Bang: River At The End Of The Universe
River assists the Doctor (Matt Smith) and Amy as they travel to the Pandorica, protecting it from the Alliance until they break through and lock the Doctor away. River is caught in a time loop that the TARDIS puts her in to protect her, and later she can be seen killing a Dalek who she makes beg for mercy.
The episode features her as a supporting character and while it doesn't delve too deeply into her, it gives her some great momens, and a nice, mellow scene at the end with the Doctor who probes her on whether he can trust her.
4 The Impossible Astronaut/ Day Of The Moon: All About River
The Impossible Astronaut and Day of the Moon take the Doctor (Matt Smith) and co to Utah in America. River joins the Doctor, Amy, and Rory; having been invited via a TARDIS-blue envelope. She, Amy, and Rory watch as the future Doctor is killed by the astronaut, and she is crucial to helping the team take on the Silence and win.
This two parter gives River gun-toting action scenes, a kiss with the Doctor, and in retrospect is heavily about her, since the child featured throughout is a kidnapped River as a child. Audiences who enjoy franchises that kill off protagonists will enjoy this particular two-parter.
3 The Angels Take Manhattan: Melody Malone
The Angels Take Manhattan is another important episode for River, as she helps the Doctor (Matt Smith), Amy, and Rory to take on the Weeping Angels in 1940s New York. There's lots of interplay between her and the Doctor that develops along their relationship, and even has a sequence showing River masquerading as an investigator named Melody Malone.
While the episode largely centers on Amy and Rory and their departure, it still finds time to give River a lot of developing scenes, and she is a big source of support for the Doctor when losing his friends to the Weeping Angels. While this episode isn't important to River's overall main questline, it is one of her best side quests.
2 Let's Kill Hitler: The First Steps
Let's Kill Hitler features the Doctor (Matt Smith) and River's first meeting, from her point of view. It also turns out that her previous incarnation Mels (Nina Toussaint-White) was the best friend of Amy and Rory while they were growing up, who were unaware of her true identity.
Killed by Hitler, and touring around war-torn Berlin in the beginning of her River Song incarnation, this episode is perhaps the most important episode for the character. It shows a very different River from all of the other episodes and has her learning a lot about herself, and choosing to do right rather than easy.
1 The Husbands Of River Song: The Marriage Heist
The Husbands of River Song is the Twelfth Doctor's first episode and only episode to feature River Song. Pulling off a heist involving multiple husbands, she runs into the Doctor without knowing that's who he is, due to the change in face. The Doctor plays along with this, and it is not until late in the episode that he reveals to her who he is.
Capaldi and Kingston have great chemistry together and are given a lot of great material to work with. The episode also closes the book on River's character, with her getting to spend time with the Doctor on Darillium for years, before going off to the library.