- Several, particularly in The ABC Murders when Cust shows up to emotionally thank Poirot for clearing his name and saving him from the gallows. Basically, any time Poirot saves an innocent person falsely accused of a crime, but Cust is especially heartwarming because of the poor guy's status as The Woobie.
- In The Mysterious Affair at Styles, when Hastings stumbles into Poirot at the store while talking with the clerk, Poirot calls out, "Hastings?" Then, when both Poirot and Hastings recognize each other, they let out a Squee! of excitement as reaction and hug each other, both being glad to see each other again, Poirot calling out in excitement, "Mon ami!!"
- It's especially heartwarming in context, with Poirot having become a refugee and Hastings recently off the front.
- Also in the episode, when Japp shows up with one of his superiors and notes Poirot's warnings about not arresting Alfred Inglethorp despite the evidence pointing towards him. The fact that Japp believes him immediately despite the two's occasional clashes and general Snark-to-Snark Combat throughout other episodes really says a lot about the trust he has in his peculiar friend.
- In The Murder of Roger Ackroyd, Poirot is surprised to find Inspector Japp as a familiar face. As a result, he lets out a Squee! of excitement, and though Poirot is too fat to hug him, he has to shake hands with the Inspector.
- Poirot uniting Eleanor Carlisle with the loyal Dr. Lord at the end of Sad Cypress.
- In "Miss McGinty's Dead", the scene where Poirot reunites James Bently (who Poirot has just saved from the Gallows) with the woman he loves.
- Poirot seeing that he has managed to finally bring some peace and happiness to the troubled Norma Restarick at the end of Third Girl.
- In the episode "Double Sin", Poirot has been suffering from depression, and slips into a lecture Inspector Japp is giving on police work. He hears Japp speak very negatively on Private Detectives ... then he hears Japp mention that Poirot is the one exception to the rule, and compliments him as a fine and worthy comrade. This heartens Poirot and inspires him to solve the case.
The professional private detective, ladies and gentlemen, is not the glamorous figure of fiction. He is a man who, failing in more worthy walks of life and being of meddlesome and troublemaking disposition, finally comes to rest in a dingy office over the chip shop, where he plies for hire in the sordid world of petty crime and divorce. Except, I have to say, for one. I have been fortunate in my career, in that many - in fact most of my cases have been shared with the most extraordinary of private detectives and, if I may borrow a word from his own native tongue, that doyen of the Belgian police force, Monsieur Hercule Poirot. I think I may say without fear of contradiction that Hercule Poirot has one of the most original minds of the 20th century. Intelligent, brave, sensitive, devastatingly quick, Hercule Poirot stands head and shoulders above any other detective of my considerable experience.
- Japp's speech itself shows how much he holds Poirot in high regard.
- A very bittersweet one from Curtain: "They were good days. Yes, they have been good days."
- Meta-wise: before the filming of the final telemovies, David Suchet specifically asked the producers to film Dead Man's Folly after Curtain, because he didn't want his last time playing Poirot to be his death scene.
- A small moment from "Four and Twenty Blackbirds" when Poirot cooks Hastings dinner. Despite the former's consistent teasing of the latter, clearly he cares about his friend.
- The ending of Peril at End House as well, when Poirot and his three friends, having just successfully wrapped up a mystery together, enjoy ice cream on the shore. Even Japp is invited!
- "The Double Clue" involves Japp afraid he's about to lose his job if he can't figure out a case. With Poirot seemingly distracted by Countess Vera Rosakoff, Hastings and Miss Lemon step in to try to help Japp instead. While they don't get particularly far, it's sweet that they try to help.
- The end of The Dream has a moment that's both funny and heartwarming. Poirot buys Miss Lemon a gift. She thinks it's a new typewriter, which she'd asked for earlier. It's actually a clock, to spare her having to look out the window to find a clock. Miss Lemon isn't as enthusiastic about the clock as she would have been about a typewriter. Poirot remains blissfully oblivious and thinks he's done her a good turn, and in a way he has; even though his choice of gift was misguided, it's clear he really does care about her and Hastings.
Heartwarming / Poirot