From Rose to Ruby Sunday… which companion exit moved you the most?
Mine are Martha And Amy.
Martha’s was realistic and that to me was a breath of fresh air in a way. Then she moved on to bigger things I would say great for her.
Amy leaving because of Rory … does it sound corny if I cry every time I see the end of Angels take Manhatten?
But dont limit yourselves we can expand to audios, books, etc.
Just wanted to start here 
Not corny at all, or if it is then I am the exact same!
I think the question you’re asking - best exit - is different to the question I immediately considered - best final episode. Of course, how much I like some of the episodes makes a difference to how I feel, but I think exits that felt most fitting of the characters were Martha and Clara. With Martha, the choice to leave is powerful and perfect, and gives her an agency that is sadly lacking in many of her other episodes. And for Clara, I think the melodrama and tragedy is perfect too because she was never going to leave the Doctor unless she had to, through death or anything else.
And will it surprise anyone if I say Lucie Miller… I just really love To the Death okayyyyy 
Great question! It made me think! And I think I have more opinions on exits I didn’t like haha
Donna - my wife was distraught at her original ending.
Adam. It was great that he departed.
Amy/Rory - It was an actual exit. No coming back. No fake-out.
Valarie - Experienced a lot, and had to figure s**t out.
I’m going to go for what might be an unpopular choice, and say Nardole in The Doctor Falls.
It felt like a really mature take on a companion exit. He knows the fight he’s going to take on can’t be won, but he’ll do it anyway, because any extra time won for the spaceship’s children is worth it. It’s sad but hopeful like the whole of the episode. It’s also done out of mutual respect between him and the Doctor, and a great conclusion to their (actually very interesting and unique) relationship.
@sircarolyn No, I had no idea you were a fan of Lucie Miller 
And Delta, yes…. Donna’s first exit made me mad. I loved her. So I was glad to see her return.
Exactly… @ItsR0b0tNinja No returning from that.
It just was so sad and romantic cause they love each other.
So whaddya do.
I liked Nardole’s exit too.
@SweetAIBelle Shame on you
I know, we were all probly happy to see him go.
The reason I site those two is that nearly all the others have no impact on me. A companion leaving in the Revival is just an afterthought… well in most of DW, actually.
Probably a very unpopular opinion but Rose in Doomsday. I never was a fan of Rose, remember being over the moon when she left in season two as a kid.
Doesn’t help that the Yvonne Hartman is right there either
Adding my favourite companion exits from the EU!
Evelyn Smyth’s exit in A Death in the Family is heartbreaking and perfect.
And it’s not exactly a companion exit story, but the Short Trip (from the book Companions) Kept Safe and Sound is one of my favourite ever Doctor Who stories, and is a wonderful final note for (at least one version of) K9.
@teslapunk3327 Hey I get it.
It was a shock and gut wrenching.
But she kept coming back. 
I’ll say Ace’s exit. But I won’t say which one.
Or when they killed Rory.
Or when they killed Clara.
Actually, I think the best one is Donna’s exit in Journey’s End. It’s so sad and poignant, especially because you know we’ll never see her again.
My first instinct and I think the one most in line with how I feel is Rose. I was never the biggest fan of her character but I like the finality and uniqueness of her ending. Sure, she’s come back since then but it really felt like a costly separation, but one that is bittersweet since she does get to live with an alternate version of her family (and even her own alternate Doctor eventually).
Martha and Mickey I think have easily the best exits of the revival, although Martha’s unfortunately happens in an otherwise very weak episode. I’d say the best revival stories featuring companion edits, though, are Bad Wolf/The Parting of the Ways, World Enough and Time/The Doctor Falls, and on a bit of a technicality, The God Complex.
I liked Martha’s exit. No world-ending reason just that she wants to be with her family. Especially when we meet her again and she has a career and stuff.
Dan in The Power of the Doctor.
“I don’t want to push me luck any further”
So relatable really.
And Graham leaving the TARDIS life that he loves so much to spend time with his Grandson, but still can’t resist to play act Volcano Inspector afterwards 
And then starts companions united
Rory was done dirty, all focus was on Amy when the Doctor’s Father-in-law was just as much a part of the Doctor’s mad life.
Donna’s was heartbreaking, and that’s why I really don’t like that it was reversed honestly.
Martha, 10 treated her terribly.
Donna’s is certainly one of my favourites. I actually think her coming back doesn’t make it any less heartbreaking, that first scene in the star beast makes it very clear she, for all that her life is beautiful, has been suffering for all that time. Just, losing your memory is so much worse than most other things happening to companions to me.
Yaz’s is also a favourite, it just feels so normal, for lack of a better word, heartbreaking. There’s no giant monsters, no alternate worlds, just time running out, and ice cream.