Marie is the only one during the "talking pillow" debate that decides to side with Walt by telling him that he should do what he wants and agreeing with the sentiment that spending time in chemo is not exactly the best way to go. This quickly derails into an argument, but it's a first sign that Marie is more than just the obnoxious sister.
Hugo, the janitor at the high school where Walt works, cleans up the chemo-induced vomit and offers Walt a stick of gum for his breath. The guy's so soft-spoken and genuine…
Hugo:I'll take care of it, Mr. White. You've got students to teach.
Walt Jr. reaction to a bald Walt also counts. Skyler is shocked and dumbstruck, the kid calls him a badass. Everyone would show Tuco after such positive reinforcement at breakfast.
Walt showing for the first time he cares about Jesse when he storms Tuco's place to demand the money he owes them AND 15 grand for Jesse. And he doesn't drop his cool for a single moment.
Another little one is the look on Jesse's face when Walt gets back and he asks him what happened. You can tell that he's trying hard not to look too pleased at the idea that Walt was "out for blood" after hearing that someone had hurt him, but that he's actually quite touched.
Despite having a blowup minutes earlier, Walt offers Jesse breakfast in his own house in "Down". (And, one hopes, a shower.)
Jesse's last line in "Peekaboo": "You have a good rest of your life, kid."
At the end of "4 Days Out", Jesse reassures Walt that if anything happens, Jesse will give Walt's family their due money.
Also Walt and Jesse high-fiving once they realise they've just cooked enough meth in 4 days to make them $672,000 each.
Hank crying on Marie's shoulder in the elevator after having a very long and bad day in "One Minute".
In the previous two episodes, Hank goes to track Heisenberg and finds Walt and Jesse's RV with them inside, but gets a phone call telling him Marie is in the hospital. After realizing it was a trick he goes to Jesse's house and beats him unconscious. After being suspended from the DEA and told he he's facing serious charges he finally sees Marie.
Walt comforting Marie in the hospital. She wonders aloud how "anyone could survive this deathtrap," to which Walt ultimately responds, "I survived this place. And I'm not half the man your husband is."
When Skyler "reveals" the gambling tale to Marie, Skyler especially emphasizes that Walt only wanted to save his family from financial troubles when he's deceased, indicating that in spite of Skyler's understandable reservations about having a meth-cooking husband, she has come to see Walt's good intentions for his cooking.
At the end of "Fly", Jesse takes Walt, who has fallen asleep in his chair, and lies him down on a sofa, putting a blanket over him.
"Half Measure", after Jesse yells at Walt for ratting him out to Gus about his plan to kill the dealers that had Combo killed, not knowing they work for Gus, Gus takes a moment to tell him that Walt is the only friend he has in the room at the moment, when he found out about the plan it wasn't from him, and if not for his respect for Walt, Gus would be handling the problem in a "different manner".
"Run" Walter saving Jesse from two drug dealers by running them over with his car and telling him to escape. This is after Walter warns Jesse that he won't be able to protect him since he was stealing meth from the lab, and also spends the whole time lecturing Jesse how killing 2 of Gus' drug dealers would be disaster.
The framed picture Tio keeps in his nursing room of his nephews when they were kids.
Walt telling Gus that he's his only hope to keep the meth business running, so Gus can't kill him, then adding that he also won't do the work if Gus kills Jesse.
During his speech to Gus, he also puts Jesse's name first most of the time, making it clear that while he wants to keep his head, allowing Jesse to be harmed is not worth it.
Jesse pays him back (though unfortunately not with Walt as witness) when Gus seems to be asking him if he could take over the lab if Walt were killed, and Jesse says that Gus will have to kill him too if that happens.
The Season 4 finale. Walt showing up to rescue Jesse when he's chained up in Gus' lab. The cavalry's here, bitch!
"Bullet Points": Walt's anger towards Jesse for his neglectful behavior turns into anger for Gus' organization when Walt realizes Pinkman is missing. The expression on his face when he asks where he is to the camera in the meth lab makes it clear that Walter White is out for blood.
Walt Jr. in "Salud". He spends his day comforting Walt, who is in a pathetic state after his fight with Jesse, cleaning his house and fixes his glasses. The amount of devotion the kid holds to his obviously flawed dad almost reminds you of the times when Walt's crimes were justified.
Jesse pleads with Gus to let Walt go. This, after Jesse proves himself to be more of an asset than Walt and even after their disastrous fight in "Bug".
Mike with his granddaughter.
Made even sweeter in season 5 where we find out he had a slush fund in her name with two million bucks in it. Mike isn't just working to support himself, he's doing it to ensure his granddaughter has a future (drawing a parallel between Walt) and it is the concern for her future that motivates him to go against his own judgment and work with Walter White.
Mike leaving a giant load of cash for his granddaughter in a safety deposit box, to be given to her on her 18th birthday.
Walt giving a hundred dollar tip to his Denny's waitress, as he apparently goes off to die in a blaze of glory.
Jesse giving Walt a present for his 51st (51 stone = 714 lbs) birthday.
A meta example, but Johnathan Banks's comments in regards to his departure from the show, and Mike's death qualify as this.
"This is a glorious end to a magnificent character, that I've been lucky enough to play. So now you know, I'm a cupcake. 46 years professionally, and this is as good as it's ever been. Thank you."
In "Gliding Over All" Walt shows up at Jesse's house and leaves him duffel bags full of cash after previously denying him his buyout.
Hank playing with Holly in "Dead Freight". Holly also utters her first words, "mama!"
Jesse's first thought on what to do with his five million dollars: give half to Mike's granddaughter, and the other half to the parents of the boy killed at the train heist.
This troper thought that it was rather heartwarming to see Walt talking business with Skylar about where to put the air fresheners, before talking about buying a second car wash. Before laundering money comes up, they sounds like two people running an honest business, leading a normal life. Kinda of heads into tearjerker territory though, when you consider that Walt could have avoided ever being involved in the meth business if he had just taken that job at Grey Matter. Maybe he and Skylar could've opened up an honest business funded by clean money.
Walt's moment of vulnerability after collapsing due to exhaustion with Skyler. He says that he knows Skyler must have went for a deal and that he'll make it easy and turn himself in and all he wants is for Skyler to not give out the money to the DEA, just sit on it and give it to the kids, just as he intended. It's heartbreaking to see the original Walter White for a moment there - a deeply flawed man who brought all of this on himself, but in the end just wanted to leave something for his children.
Walt's Cool Down Hug to Jesse. It's no longer possible to tell if it was even a bit genuine, but it still a bit nice to see it, considering how hard Jesse needed something like this and how even Walt seems to be shaken by his plea not to jerk him around anymore.
And it seems it actually was genuine given the next episode, where even after Jesse almost burns the house down, Walt insists on doing everything he can to resolve the situation without Jesse getting hurt.
Walt giving Walt Jr. a heartfelt hug after his son gets upset over the possibility of losing his father to cancer.
Walt is finally cornered, caught by Hank with hard evidence as he, Gomez, and Jesse arrive to arrest him. His first instinct is to call Todd for a rescue, but then he looks at them again and realizes that even with as far as he's sunk, this is a step he can't take, so he tells Todd to forget it, and gets a look of absolute peace on his face as Hank calls for him to come out.
Hank telling Marie that he loves her when he arrests Walt. What makes it very sad but heartwarming too that this was the last time he spoke to her.
Walt leaving Holly at the fire department, after having taken her when fleeing from his house. At least it shows he still has some shred of a conscience.
And in the process, making a call to Skyler, knowing the police are there, in which he portrays himself as a terrifying villain who kept Skyler in line through fear throughout the series, exonerating her of any related charges.
Walt offering Jack his entire money stash to not kill Hank, proving once and for all that underneath the ruthlessness, manipulations and greed Walt values his family more than his money. Dean Norris said that moment redeemed Walt in Hank's eyes, at least partially.
Hank's way of telling Walt that his pleading is pointless - he says that even though Walt is the smartest man he has ever met, he still can't understand that Jack has made the decision 10 minutes ago. It not only points out how heartbreaking it was for Hank to learn that Walt is Heisenberg, but also underlining the large respect he felt towards his brother-in-law's intellect. It's also delivered in a surprisingly quiet and tender tone, showing a sign of that feeling of partial redemption Norris mentioned Hank felt Walt had achieved.
Even after everything that's happened, Marie still struggles to forgive Skyler, and tries to make what she thinks is Walt's downfall as easy on her and Walter Jr. as possible, letting Skyler be the one to tell him.
One of the sole bright spots of Ozymandias is ironically Walter becoming the mask one last time in order to provide Skyler an alibi. Skyler slowly recognizes what exactly it is he is doing and goes along with it.
Walt giving Skyler the lottery ticket with the coordinates for her to use as a bargaining chip. This will also allow Hank and Gomez to receive a proper funeral, giving closure to their loved ones.
Walt admitting he wasn't in the meth business for the family, it was for himself. That may sound oddly warped, but in truth, it was heartwarming because he had spent the whole show lying and he finally gave her the truth she and the rest of his family deserved to hear.
Walt's last goodbye to his daughter Holly, just stroking her hair in silence.
Walt watching Flynn return home from afar. He seems at peace knowing that his son will receive the money even though his son still hates him and will never know the money came from him.
In a warped sense, Walt tackling Jesse to the ground so that he wouldn't get mowed down by the M60, thus letting him live. Word of God is that Walt was going to let Jesse die until the moment before the machine gun went off, as he just couldn't hurt the kid. Bonus points for Walter, if viewed a second time, is completely shielding Jesse from the side the machinegun is going off, makes the scene even more heartwarming.
After EVERYTHING that's happened, Walt and Jesse looking at each other one last time... They can't bring themselves to fully get over what they did to each other and they know this is goodbye, giving each other final nods of understanding.
Jesse, finally free, driving away, laughing and crying at the same time.
Walt taking one final stroll through the superlab before dying, with the knowledge that despite his motivations his family will be exempt from blame and provided for, and that they and Jesse will be safe.
Walt died beating his cancer, it's reveal caused the entire series events and he still managed to beat it the punch and die on his own terms, knowing that he did not die with nothing left for his family as he initially feared would happen.
A meta example for the band Badfinger, whose song "Baby Blue" closes out the series with Walt's death. After reaching the height of fame in the 70's, the band suffered a series of professional and personal misfortunes which culminated with two band members committing suicide, and went into relative obscurity. Following the use of their song in the finale, it was reported that online streams of "Baby Blue" have gone up astronomically.
Also a meta example: One devoted fan group put an obituary to White in the October 4, 2013 issue of the Albuquerque Journal:
White, Walter AKA "Heisenberg," 52, of Albuquerque, died Sunday after a long battle with cancer, and a gunshot wound. A co-founder of Gray Matter, White was a research chemist who taught high school chemistry, and later founded a meth manufacturing empire. He is survived by his wife Skyler Lambert; son Walter "Flynn" Jr.; and daughter Holly. A private memorial was held by his family. In lieu of flowers, donations can be made to a drug abuse prevention charity of your choice. He will be greatly missed.
Then on October 19, 2013, some people carried out a mock funeral procession (including a hearse and a replica of White's meth lab RV) and a funeral service was held at Albuquerque's Sunset Memorial Park cemetery. A headstone placed with a photo of Cranston as White read, "Beloved Husband, Father, Teacher & Entrepreneur: R.I.P. Walter White (September 7, 1959 — September 7, 2011)".